1999999999999999999979

This number is a prime.

                                                    19 9999999999 9999999979

+ The only non-titanic prime of form p=2*10^n-n, where n is a composite, (n=21). [Loungrides]

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