77777...31313 (27-digits)

This number is a prime.

                                               7777777 7777771313 1313131313

+ Thirteen 7's followed by seven 13's is prime. "Lucky 7" and "Unlucky 13" keeping each other in perfect balance. [De Geest]

Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell