111181111

This number is a prime.

+

  1 1 1
  1 8 1 
  1 1 1
The smallest square-congruent prime.

+ The largest palindromic near-repunit prime whose digital length is equal to the sum of its distinct digits. [Loungrides]

Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell