This number is a prime.
(10^1410-1)/9+5*10^655 is the smallest titanic near-repdigit prime that gives a different prime when rotated by 180 degress about an axis perpendicular to the page. Its twin prime is (10^1410-1)/9+8*10^754. [Broadhurst]
Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell