91111...11119 (247-digits)

This number is a prime.

                                    9111111 1111111111 1111111111 1111111111
1111111111 1111111111 1111111111 1111111111 1111111111 1111111111 1111111111
1111111111 1111111111 1111111111 1111111111 1111111111 1111111111 1111111111
1111111111 1111111111 1111111111 1111111111 1111111111 1111111111 1111111119

+ 8*10246+(10247-1)/9+8 was the largest known depression prime in 1991. [Caldwell]

(There is one curio for this number that has not yet been approved by an editor.)

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