Checking whether a certain number is prime












1












$begingroup$


Using the primality test on this site, I found that the concatenation of the digit reversal of the first 548 odd primes in the reverse order is a prime!. It is only a 1998-digit prime, but it took more than an hour for the site's calculator to state that it is a prime.



The calculation went super slowly. Could someone here confirm that this result is correct?.



The result I got is 7693749334931393 ... 91713111753.










share|improve this question









New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$








  • 1




    $begingroup$
    Are you asking how to check if a number is prime using Mathematica? If so, try PrimeQ.
    $endgroup$
    – bobthechemist
    4 hours ago






  • 1




    $begingroup$
    Here's a free (fast) way to test this. It gives True in under a second. It's just building off free Wolfram Cloud stuff so you can give that a check too if you need something else like this. It takes like half a second for the notebook to load, but after that you can do whatever with it.
    $endgroup$
    – b3m2a1
    3 hours ago












  • $begingroup$
    Welcome to Mathematica.SE. Are you sure you are posting on the right site? There is nothing in your question making it clear that it is concerned with Mathematica software.
    $endgroup$
    – m_goldberg
    3 hours ago
















1












$begingroup$


Using the primality test on this site, I found that the concatenation of the digit reversal of the first 548 odd primes in the reverse order is a prime!. It is only a 1998-digit prime, but it took more than an hour for the site's calculator to state that it is a prime.



The calculation went super slowly. Could someone here confirm that this result is correct?.



The result I got is 7693749334931393 ... 91713111753.










share|improve this question









New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$








  • 1




    $begingroup$
    Are you asking how to check if a number is prime using Mathematica? If so, try PrimeQ.
    $endgroup$
    – bobthechemist
    4 hours ago






  • 1




    $begingroup$
    Here's a free (fast) way to test this. It gives True in under a second. It's just building off free Wolfram Cloud stuff so you can give that a check too if you need something else like this. It takes like half a second for the notebook to load, but after that you can do whatever with it.
    $endgroup$
    – b3m2a1
    3 hours ago












  • $begingroup$
    Welcome to Mathematica.SE. Are you sure you are posting on the right site? There is nothing in your question making it clear that it is concerned with Mathematica software.
    $endgroup$
    – m_goldberg
    3 hours ago














1












1








1


1



$begingroup$


Using the primality test on this site, I found that the concatenation of the digit reversal of the first 548 odd primes in the reverse order is a prime!. It is only a 1998-digit prime, but it took more than an hour for the site's calculator to state that it is a prime.



The calculation went super slowly. Could someone here confirm that this result is correct?.



The result I got is 7693749334931393 ... 91713111753.










share|improve this question









New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




Using the primality test on this site, I found that the concatenation of the digit reversal of the first 548 odd primes in the reverse order is a prime!. It is only a 1998-digit prime, but it took more than an hour for the site's calculator to state that it is a prime.



The calculation went super slowly. Could someone here confirm that this result is correct?.



The result I got is 7693749334931393 ... 91713111753.







prime-numbers






share|improve this question









New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 13 mins ago









Henrik Schumacher

50.4k469144




50.4k469144






New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 4 hours ago









Toni SToni S

132




132




New contributor




Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Toni S is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








  • 1




    $begingroup$
    Are you asking how to check if a number is prime using Mathematica? If so, try PrimeQ.
    $endgroup$
    – bobthechemist
    4 hours ago






  • 1




    $begingroup$
    Here's a free (fast) way to test this. It gives True in under a second. It's just building off free Wolfram Cloud stuff so you can give that a check too if you need something else like this. It takes like half a second for the notebook to load, but after that you can do whatever with it.
    $endgroup$
    – b3m2a1
    3 hours ago












  • $begingroup$
    Welcome to Mathematica.SE. Are you sure you are posting on the right site? There is nothing in your question making it clear that it is concerned with Mathematica software.
    $endgroup$
    – m_goldberg
    3 hours ago














  • 1




    $begingroup$
    Are you asking how to check if a number is prime using Mathematica? If so, try PrimeQ.
    $endgroup$
    – bobthechemist
    4 hours ago






  • 1




    $begingroup$
    Here's a free (fast) way to test this. It gives True in under a second. It's just building off free Wolfram Cloud stuff so you can give that a check too if you need something else like this. It takes like half a second for the notebook to load, but after that you can do whatever with it.
    $endgroup$
    – b3m2a1
    3 hours ago












  • $begingroup$
    Welcome to Mathematica.SE. Are you sure you are posting on the right site? There is nothing in your question making it clear that it is concerned with Mathematica software.
    $endgroup$
    – m_goldberg
    3 hours ago








1




1




$begingroup$
Are you asking how to check if a number is prime using Mathematica? If so, try PrimeQ.
$endgroup$
– bobthechemist
4 hours ago




$begingroup$
Are you asking how to check if a number is prime using Mathematica? If so, try PrimeQ.
$endgroup$
– bobthechemist
4 hours ago




1




1




$begingroup$
Here's a free (fast) way to test this. It gives True in under a second. It's just building off free Wolfram Cloud stuff so you can give that a check too if you need something else like this. It takes like half a second for the notebook to load, but after that you can do whatever with it.
$endgroup$
– b3m2a1
3 hours ago






$begingroup$
Here's a free (fast) way to test this. It gives True in under a second. It's just building off free Wolfram Cloud stuff so you can give that a check too if you need something else like this. It takes like half a second for the notebook to load, but after that you can do whatever with it.
$endgroup$
– b3m2a1
3 hours ago














$begingroup$
Welcome to Mathematica.SE. Are you sure you are posting on the right site? There is nothing in your question making it clear that it is concerned with Mathematica software.
$endgroup$
– m_goldberg
3 hours ago




$begingroup$
Welcome to Mathematica.SE. Are you sure you are posting on the right site? There is nothing in your question making it clear that it is concerned with Mathematica software.
$endgroup$
– m_goldberg
3 hours ago










2 Answers
2






active

oldest

votes


















4












$begingroup$

You are right!!



Reverse /@ Table[IntegerDigits[Prime[i]], {i, 2, 549}] // Reverse // 
Flatten // FromDigits // PrimeQ



True



7693749334931393929332939193719311937093988318837783368335831583748333
8332831283308379733973977396737673167393733373727391739073107379631963
7763376317639563346373631363326371633163706339533853185317539553755374
5314539353335392537253715311539943194396437643364316437543944333433143
7043193398333733173316339533743334331333923332339133313370331033992317
2395237523352315239223122371239023302319137813181396137613361373131213
9113901398033803970376031603940314037303320391031103100399921792969236
9275923592939272927192909230927982788297821682758215823482738233829182
3082108279721972987277727672357294721472137292729172317211727072996239
6298627862386277621762366295627562746233621262716290623952195297527552
1552945234529352135212523052774237427642954274421442734232427142114299
3239329832383218327732173275321532743214329332333211329032792239227822
1822372296227622152234229322732212223122702230229712161235123412141273
1213129212311211129902980278023802180296023602350293029202720271021102
3002999179913991789197913791159194913391139131917091109198819781778137
8117817681168174811381328111811081987178713871777195713571747114713371
3271127190719961796139619661766136617561736172611261916131619061706110
6179513851975117517651955135519451345113513251115199413941984178413841
1841174195413541154174419341334192417241324190419931183137317631163172
3112319131703130311031792119219821382197217721952194217321132192213221
7121312110213911781118111711361135111511921132117111901130117901390119
0178019601360116011501940193013301130112019101310190017991993897791797
6935974914973992991911970978838818877836895875835893892872832812811890
8797787377967167757157347937337727917907107196386776376166956356746346
1461369167163167061069953957857751759653657557451453251259053059941947
8497476436416475494434493433413412491490410479398338397337376395335394
3743733133713313113703392382182772172962362752152142932332922722322112
9917913911911819713717613617511519419317311317213119017013011017998389
73717761695357434147313923291713111753







share|improve this answer









$endgroup$













  • $begingroup$
    AAHHHH..., I LOVE YOU MAN !!!!!
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    I WILL REMEMBER YOUR NAME !!! : D
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    Glad to help..!
    $endgroup$
    – Okkes Dulgerci
    3 hours ago



















0












$begingroup$

junk = Table[
FromDigits@Reverse@IntegerDigits[Prime[i]], {i, 2, 549}];
final = FromDigits[Flatten[IntegerDigits /@ junk]];
PrimeQ[final]


(*



False



*)



This takes $0.002238$ seconds on a Mac laptop.






share|improve this answer









$endgroup$













  • $begingroup$
    Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    @ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
    $endgroup$
    – David G. Stork
    4 hours ago












  • $begingroup$
    Damn it !! I hate this !
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    Are you sure the first digit of this prime is 769374933493... ?
    $endgroup$
    – Toni S
    3 hours ago






  • 1




    $begingroup$
    Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
    $endgroup$
    – David G. Stork
    3 hours ago











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "387"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});






Toni S is a new contributor. Be nice, and check out our Code of Conduct.










draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f189569%2fchecking-whether-a-certain-number-is-prime%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









4












$begingroup$

You are right!!



Reverse /@ Table[IntegerDigits[Prime[i]], {i, 2, 549}] // Reverse // 
Flatten // FromDigits // PrimeQ



True



7693749334931393929332939193719311937093988318837783368335831583748333
8332831283308379733973977396737673167393733373727391739073107379631963
7763376317639563346373631363326371633163706339533853185317539553755374
5314539353335392537253715311539943194396437643364316437543944333433143
7043193398333733173316339533743334331333923332339133313370331033992317
2395237523352315239223122371239023302319137813181396137613361373131213
9113901398033803970376031603940314037303320391031103100399921792969236
9275923592939272927192909230927982788297821682758215823482738233829182
3082108279721972987277727672357294721472137292729172317211727072996239
6298627862386277621762366295627562746233621262716290623952195297527552
1552945234529352135212523052774237427642954274421442734232427142114299
3239329832383218327732173275321532743214329332333211329032792239227822
1822372296227622152234229322732212223122702230229712161235123412141273
1213129212311211129902980278023802180296023602350293029202720271021102
3002999179913991789197913791159194913391139131917091109198819781778137
8117817681168174811381328111811081987178713871777195713571747114713371
3271127190719961796139619661766136617561736172611261916131619061706110
6179513851975117517651955135519451345113513251115199413941984178413841
1841174195413541154174419341334192417241324190419931183137317631163172
3112319131703130311031792119219821382197217721952194217321132192213221
7121312110213911781118111711361135111511921132117111901130117901390119
0178019601360116011501940193013301130112019101310190017991993897791797
6935974914973992991911970978838818877836895875835893892872832812811890
8797787377967167757157347937337727917907107196386776376166956356746346
1461369167163167061069953957857751759653657557451453251259053059941947
8497476436416475494434493433413412491490410479398338397337376395335394
3743733133713313113703392382182772172962362752152142932332922722322112
9917913911911819713717613617511519419317311317213119017013011017998389
73717761695357434147313923291713111753







share|improve this answer









$endgroup$













  • $begingroup$
    AAHHHH..., I LOVE YOU MAN !!!!!
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    I WILL REMEMBER YOUR NAME !!! : D
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    Glad to help..!
    $endgroup$
    – Okkes Dulgerci
    3 hours ago
















4












$begingroup$

You are right!!



Reverse /@ Table[IntegerDigits[Prime[i]], {i, 2, 549}] // Reverse // 
Flatten // FromDigits // PrimeQ



True



7693749334931393929332939193719311937093988318837783368335831583748333
8332831283308379733973977396737673167393733373727391739073107379631963
7763376317639563346373631363326371633163706339533853185317539553755374
5314539353335392537253715311539943194396437643364316437543944333433143
7043193398333733173316339533743334331333923332339133313370331033992317
2395237523352315239223122371239023302319137813181396137613361373131213
9113901398033803970376031603940314037303320391031103100399921792969236
9275923592939272927192909230927982788297821682758215823482738233829182
3082108279721972987277727672357294721472137292729172317211727072996239
6298627862386277621762366295627562746233621262716290623952195297527552
1552945234529352135212523052774237427642954274421442734232427142114299
3239329832383218327732173275321532743214329332333211329032792239227822
1822372296227622152234229322732212223122702230229712161235123412141273
1213129212311211129902980278023802180296023602350293029202720271021102
3002999179913991789197913791159194913391139131917091109198819781778137
8117817681168174811381328111811081987178713871777195713571747114713371
3271127190719961796139619661766136617561736172611261916131619061706110
6179513851975117517651955135519451345113513251115199413941984178413841
1841174195413541154174419341334192417241324190419931183137317631163172
3112319131703130311031792119219821382197217721952194217321132192213221
7121312110213911781118111711361135111511921132117111901130117901390119
0178019601360116011501940193013301130112019101310190017991993897791797
6935974914973992991911970978838818877836895875835893892872832812811890
8797787377967167757157347937337727917907107196386776376166956356746346
1461369167163167061069953957857751759653657557451453251259053059941947
8497476436416475494434493433413412491490410479398338397337376395335394
3743733133713313113703392382182772172962362752152142932332922722322112
9917913911911819713717613617511519419317311317213119017013011017998389
73717761695357434147313923291713111753







share|improve this answer









$endgroup$













  • $begingroup$
    AAHHHH..., I LOVE YOU MAN !!!!!
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    I WILL REMEMBER YOUR NAME !!! : D
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    Glad to help..!
    $endgroup$
    – Okkes Dulgerci
    3 hours ago














4












4








4





$begingroup$

You are right!!



Reverse /@ Table[IntegerDigits[Prime[i]], {i, 2, 549}] // Reverse // 
Flatten // FromDigits // PrimeQ



True



7693749334931393929332939193719311937093988318837783368335831583748333
8332831283308379733973977396737673167393733373727391739073107379631963
7763376317639563346373631363326371633163706339533853185317539553755374
5314539353335392537253715311539943194396437643364316437543944333433143
7043193398333733173316339533743334331333923332339133313370331033992317
2395237523352315239223122371239023302319137813181396137613361373131213
9113901398033803970376031603940314037303320391031103100399921792969236
9275923592939272927192909230927982788297821682758215823482738233829182
3082108279721972987277727672357294721472137292729172317211727072996239
6298627862386277621762366295627562746233621262716290623952195297527552
1552945234529352135212523052774237427642954274421442734232427142114299
3239329832383218327732173275321532743214329332333211329032792239227822
1822372296227622152234229322732212223122702230229712161235123412141273
1213129212311211129902980278023802180296023602350293029202720271021102
3002999179913991789197913791159194913391139131917091109198819781778137
8117817681168174811381328111811081987178713871777195713571747114713371
3271127190719961796139619661766136617561736172611261916131619061706110
6179513851975117517651955135519451345113513251115199413941984178413841
1841174195413541154174419341334192417241324190419931183137317631163172
3112319131703130311031792119219821382197217721952194217321132192213221
7121312110213911781118111711361135111511921132117111901130117901390119
0178019601360116011501940193013301130112019101310190017991993897791797
6935974914973992991911970978838818877836895875835893892872832812811890
8797787377967167757157347937337727917907107196386776376166956356746346
1461369167163167061069953957857751759653657557451453251259053059941947
8497476436416475494434493433413412491490410479398338397337376395335394
3743733133713313113703392382182772172962362752152142932332922722322112
9917913911911819713717613617511519419317311317213119017013011017998389
73717761695357434147313923291713111753







share|improve this answer









$endgroup$



You are right!!



Reverse /@ Table[IntegerDigits[Prime[i]], {i, 2, 549}] // Reverse // 
Flatten // FromDigits // PrimeQ



True



7693749334931393929332939193719311937093988318837783368335831583748333
8332831283308379733973977396737673167393733373727391739073107379631963
7763376317639563346373631363326371633163706339533853185317539553755374
5314539353335392537253715311539943194396437643364316437543944333433143
7043193398333733173316339533743334331333923332339133313370331033992317
2395237523352315239223122371239023302319137813181396137613361373131213
9113901398033803970376031603940314037303320391031103100399921792969236
9275923592939272927192909230927982788297821682758215823482738233829182
3082108279721972987277727672357294721472137292729172317211727072996239
6298627862386277621762366295627562746233621262716290623952195297527552
1552945234529352135212523052774237427642954274421442734232427142114299
3239329832383218327732173275321532743214329332333211329032792239227822
1822372296227622152234229322732212223122702230229712161235123412141273
1213129212311211129902980278023802180296023602350293029202720271021102
3002999179913991789197913791159194913391139131917091109198819781778137
8117817681168174811381328111811081987178713871777195713571747114713371
3271127190719961796139619661766136617561736172611261916131619061706110
6179513851975117517651955135519451345113513251115199413941984178413841
1841174195413541154174419341334192417241324190419931183137317631163172
3112319131703130311031792119219821382197217721952194217321132192213221
7121312110213911781118111711361135111511921132117111901130117901390119
0178019601360116011501940193013301130112019101310190017991993897791797
6935974914973992991911970978838818877836895875835893892872832812811890
8797787377967167757157347937337727917907107196386776376166956356746346
1461369167163167061069953957857751759653657557451453251259053059941947
8497476436416475494434493433413412491490410479398338397337376395335394
3743733133713313113703392382182772172962362752152142932332922722322112
9917913911911819713717613617511519419317311317213119017013011017998389
73717761695357434147313923291713111753








share|improve this answer












share|improve this answer



share|improve this answer










answered 3 hours ago









Okkes DulgerciOkkes Dulgerci

4,3351816




4,3351816












  • $begingroup$
    AAHHHH..., I LOVE YOU MAN !!!!!
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    I WILL REMEMBER YOUR NAME !!! : D
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    Glad to help..!
    $endgroup$
    – Okkes Dulgerci
    3 hours ago


















  • $begingroup$
    AAHHHH..., I LOVE YOU MAN !!!!!
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    I WILL REMEMBER YOUR NAME !!! : D
    $endgroup$
    – Toni S
    3 hours ago










  • $begingroup$
    Glad to help..!
    $endgroup$
    – Okkes Dulgerci
    3 hours ago
















$begingroup$
AAHHHH..., I LOVE YOU MAN !!!!!
$endgroup$
– Toni S
3 hours ago




$begingroup$
AAHHHH..., I LOVE YOU MAN !!!!!
$endgroup$
– Toni S
3 hours ago












$begingroup$
I WILL REMEMBER YOUR NAME !!! : D
$endgroup$
– Toni S
3 hours ago




$begingroup$
I WILL REMEMBER YOUR NAME !!! : D
$endgroup$
– Toni S
3 hours ago












$begingroup$
Glad to help..!
$endgroup$
– Okkes Dulgerci
3 hours ago




$begingroup$
Glad to help..!
$endgroup$
– Okkes Dulgerci
3 hours ago











0












$begingroup$

junk = Table[
FromDigits@Reverse@IntegerDigits[Prime[i]], {i, 2, 549}];
final = FromDigits[Flatten[IntegerDigits /@ junk]];
PrimeQ[final]


(*



False



*)



This takes $0.002238$ seconds on a Mac laptop.






share|improve this answer









$endgroup$













  • $begingroup$
    Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    @ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
    $endgroup$
    – David G. Stork
    4 hours ago












  • $begingroup$
    Damn it !! I hate this !
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    Are you sure the first digit of this prime is 769374933493... ?
    $endgroup$
    – Toni S
    3 hours ago






  • 1




    $begingroup$
    Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
    $endgroup$
    – David G. Stork
    3 hours ago
















0












$begingroup$

junk = Table[
FromDigits@Reverse@IntegerDigits[Prime[i]], {i, 2, 549}];
final = FromDigits[Flatten[IntegerDigits /@ junk]];
PrimeQ[final]


(*



False



*)



This takes $0.002238$ seconds on a Mac laptop.






share|improve this answer









$endgroup$













  • $begingroup$
    Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    @ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
    $endgroup$
    – David G. Stork
    4 hours ago












  • $begingroup$
    Damn it !! I hate this !
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    Are you sure the first digit of this prime is 769374933493... ?
    $endgroup$
    – Toni S
    3 hours ago






  • 1




    $begingroup$
    Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
    $endgroup$
    – David G. Stork
    3 hours ago














0












0








0





$begingroup$

junk = Table[
FromDigits@Reverse@IntegerDigits[Prime[i]], {i, 2, 549}];
final = FromDigits[Flatten[IntegerDigits /@ junk]];
PrimeQ[final]


(*



False



*)



This takes $0.002238$ seconds on a Mac laptop.






share|improve this answer









$endgroup$



junk = Table[
FromDigits@Reverse@IntegerDigits[Prime[i]], {i, 2, 549}];
final = FromDigits[Flatten[IntegerDigits /@ junk]];
PrimeQ[final]


(*



False



*)



This takes $0.002238$ seconds on a Mac laptop.







share|improve this answer












share|improve this answer



share|improve this answer










answered 4 hours ago









David G. StorkDavid G. Stork

23.9k22152




23.9k22152












  • $begingroup$
    Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    @ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
    $endgroup$
    – David G. Stork
    4 hours ago












  • $begingroup$
    Damn it !! I hate this !
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    Are you sure the first digit of this prime is 769374933493... ?
    $endgroup$
    – Toni S
    3 hours ago






  • 1




    $begingroup$
    Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
    $endgroup$
    – David G. Stork
    3 hours ago


















  • $begingroup$
    Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    @ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
    $endgroup$
    – David G. Stork
    4 hours ago












  • $begingroup$
    Damn it !! I hate this !
    $endgroup$
    – Toni S
    4 hours ago










  • $begingroup$
    Are you sure the first digit of this prime is 769374933493... ?
    $endgroup$
    – Toni S
    3 hours ago






  • 1




    $begingroup$
    Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
    $endgroup$
    – David G. Stork
    3 hours ago
















$begingroup$
Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
$endgroup$
– Toni S
4 hours ago




$begingroup$
Note that it is the first 548 odd primes, 3,5,7,11,13,.... and not the first 548 primes.
$endgroup$
– Toni S
4 hours ago












$begingroup$
@ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
$endgroup$
– David G. Stork
4 hours ago






$begingroup$
@ToniS: That's why the iteration starts at $i = 2$ (and goes to $549$): Because Prime[2] = 3. And Prime[548] = 3947 and Prime[549] = 3967.
$endgroup$
– David G. Stork
4 hours ago














$begingroup$
Damn it !! I hate this !
$endgroup$
– Toni S
4 hours ago




$begingroup$
Damn it !! I hate this !
$endgroup$
– Toni S
4 hours ago












$begingroup$
Are you sure the first digit of this prime is 769374933493... ?
$endgroup$
– Toni S
3 hours ago




$begingroup$
Are you sure the first digit of this prime is 769374933493... ?
$endgroup$
– Toni S
3 hours ago




1




1




$begingroup$
Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
$endgroup$
– David G. Stork
3 hours ago




$begingroup$
Nope: $35711317191329213731434ldots 193919332939293139334937493$. Over and out. Good luck.
$endgroup$
– David G. Stork
3 hours ago










Toni S is a new contributor. Be nice, and check out our Code of Conduct.










draft saved

draft discarded


















Toni S is a new contributor. Be nice, and check out our Code of Conduct.













Toni S is a new contributor. Be nice, and check out our Code of Conduct.












Toni S is a new contributor. Be nice, and check out our Code of Conduct.
















Thanks for contributing an answer to Mathematica Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f189569%2fchecking-whether-a-certain-number-is-prime%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

flock() on closed filehandle LOCK_FILE at /usr/bin/apt-mirror

Mangá

Eduardo VII do Reino Unido