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Largest known emirp[edit]

I suggest adding this to the article:

As of February 2007, the largest known emirp is 103929 − 571624798 × 101960 − 1, found by Jens Kruse Andersen in 2003.[1]

I am Jens Kruse Andersen so I suggest it here per WP:COI. PrimeHunter 16:59, 5 February 2007 (UTC)

Well this has been here for a while. Apparently no one has objected, and the source given looks pretty good. I'm taking the liberty to add it to this article. -FrankTobia (talk) 16:41, 17 December 2007 (UTC)
Thanks, but I should have updated this suggestion. "As of February 2007" makes it correct, but the end of the source shows I improved it in October, to 10^10006+941992101*10^4999+1. The source doesn't directly say "largest known" about the new emirp, but the introduction says "I’ll keep here a list of the 10 largest reversible & non-palindrome primes.". If it's acceptable as the largest known then my replacement suggestion is:
As of December 2007, the largest known emirp is 1010006+941992101×104999+1, found by Jens Kruse Andersen in October 2007.[2]
PrimeHunter (talk) 23:46, 17 December 2007 (UTC)
I've updated accordingly. As a practical matter, and to best serve the encyclopedia going forward, I think you should feel free to make these sorts of edits yourself so they don't languish on talk pages for months. In reading WP:COI it seems like, as long as you stick to verifiable facts with solid sources, you shouldn't have to worry too much about COI issues. I would suggest making the change, noting the potential conflict of interest on the talk page, and referencing it in your edit summary. And thanks again for the good info on primes! -FrankTobia (talk) 11:04, 18 December 2007 (UTC)
Thanks again. I could have made the new update when somebody else had accepted the source and considered the result worth mentioning. But the source is not optimal, I have said elsewhere I will not add new potential COI material, I'm telling many others at the help desk to avoid COI and make talk page suggestions instead, and I may soon be admin and would like to set an example. If my results are not important enough for others to notice and add without me suggesting it, then it might look bad if I added a lot of them without discussion. But another time I may notify a math editor if a suggestion is ignored for months on a rarely edited page. PrimeHunter (talk) 15:40, 18 December 2007 (UTC)


Error in the list[edit]

11 is not an Emirp because it is a palindromic prime, I removed it from that sentence:

The sequence of emirps begins 11, 13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157... (sequence A006567 in OEIS).

Kaluppollo (talk) 17:56, 23 September 2009 (UTC)

Thanks for spotting and fixing that. An IP added the false 11 a month ago in the preceding edit [1]. You don't have to post to the talk page when you correct simple errors like that. You can just make an informative edit summary when you correct it. PrimeHunter (talk) 20:00, 23 September 2009 (UTC)


I guess the sentence: All multi-digit, non-repunit permutable primes are emirps. should be read as: All multi-digit, non-repunit and non-palindromic permutable primes are emirps, since for example permutable primes, 131, 373, are not repunits and are palindromic primes, and therefore are not emirps. --xJaM (talk) 01:22, 20 November 2009 (UTC)

You are right. But single-digit and repunit numbers are palindromic so we only need All non-palindromic permutable primes are emirps. I have changed it to this. PrimeHunter (talk) 01:52, 20 November 2009 (UTC)

Added definition of 'emirpimes'[edit]

I took the liberty of simply adding this word to the stub article here as a subject warranting mention at least, for now.Julzes (talk) 22:12, 9 March 2011 (UTC)


Is emirpimes in the article a typo and is it supposed to read emirprimes or am I just missing something? -- Toshio Yamaguchi (tlkctb) 13:03, 6 November 2012 (UTC)

emirpimes is correct. It's semiprime spelled backwards, just like emirp is prime spelled backwards. See for example PrimeHunter (talk) 16:47, 6 November 2012 (UTC)
Makes sense. Thanks. -- Toshio Yamaguchi (tlkctb) 17:24, 6 November 2012 (UTC)