Talk:Titanic Prime whose Digits are all Prime

Apparently the number here is not prime (has $6043$ as a factor), but:


 * $7352 \times \dfrac {10^{1104} - 1} {10^4 - 1} + 1$

apparently is.

(By intuition I switched $3$ and $5$. No more further arrangements of $7,3,5,2$ are primes for those interested.)

Was it a typo in Ribenbiom's book (or Dubner's report), since I saw this number in the last page of this article of his as well?

https://www.researchgate.net/publication/237778627_Prime_Number_Records

--RandomUndergrad (talk) 07:45, 6 March 2022 (UTC)


 * Excellent catch.


 * The fact that Ribenboim's book was the source used by Wells, rather than the later paper, it is probable that the mistake exists in Ribenboim's book itself.


 * I will see if I can track down a copy and add it to my bookshelf.


 * I have not been able to find Dubner's original document, but I confess I haven't looked very hard yet. --prime mover (talk) 09:55, 6 March 2022 (UTC)