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 <t5k.org> © G. L. Honaker and Chris K. Caldwell