17777...77777 (121-digits)

This number is a prime.

                    1 7777777777 7777777777 7777777777 7777777777 7777777777
7777777777 7777777777 7777777777 7777777777 7777777777 7777777777 7777777777

+ A near-repdigit prime P consisting of a digit 1 followed by one hundred-twenty 7's found in the sequence of primes 17, 1777, 1777777777, 17777777777777, 1777777777777777777777777777777777777777777, etc. Curiously, the number of digits (121) and sum of digits (841) of P are both perfect squares. [Bajpai]

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