19999...99999 (3021-digits)
This number is a prime.
A 'near-repdigit' prime number is one where all digits are identical except one; this one, 2*(10^3020)-1 is such a number, and was proven prime by H. C. Williams in 1985. [Dobb]
(There is one curio for this number that has not yet been approved by an editor.)
Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell