Talk:Primes whose sum of digits is 25

The limit of primes that do not contain zeroes

For what n? (0 < n < ?) --CalmoSoft (talk) 06:27, 21 March 2021 (UTC)

I think it is possible to put an upper limit on primes whose digits sum to 25 and have no zeroes in them. The largest number with no internal zeros and a digit sum of 25 would be 1111111111111111111111111 (25 digits). --Tigerofdarkness (talk) 10:54, 21 March 2021 (UTC)

Correct, stretch goal updated. If zeroes were allowed there would be an infinite number of them. It will need reasonably decent bignum handling and a fast prime number checker. I expect this is not really do-able in asm, C, etc. I would put a reasonable (soft) upper limit of say 30 mins on this and not be too critical of anything around that. --Pete Lomax (talk) 12:34, 21 March 2021 (UTC)