11111...11111 (25-digits)
This number is a prime.
11111 1111000100 0111111111
A palindromic prime taking the form of a lozenge:
1 111 11111 0001000 11111 111 1[Silva]
Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell