This number is a prime.

+ The smallest prime formed by concatenating two consecutive 3-digit palindromic primes. Note that there are two other such primes (757727 and 787757) and none in ascending order. [Loungrides]

+ A prime number of the form 2x^2-4x+31, (case x=257). [Sandri]

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