Quote:
Originally Posted by paulunderwood
These are roughly 4200, 7000 and 8500 digits. You can get the exact values with pari/GP with length(decimal(10*2^135091)).
"3PRP" means it passes Fermat's Little Theorem test: 3^(N1)=1 mod N, which is necessary but not sufficient for a prime. With PFGW you can specify small bases with the b switch.

The number of decimal digits in 10*2^135091 would also be 2 + floor(13509*log(2)/log(10)).
It is possible AFAIK that "PRP" means that N "passes" RabinMiller to base 3; in this case, in addition to
3^(N1) == 1 (mod N), that
3^((N1)/2) == 1 or 1 (mod N).
If N satisfied the first condition but not the second, of course, a proper factorization of N would be in hand.