9137

This number is a prime.

The largest diagonal prime of order 2 with distinct digits. (A diagonal prime is a prime of n² digits (n > 1) arranged left-right, top-down, in a n-by-n matrix, where the diagonals are also prime in each direction). [Loungrides]

If we examine the possible end digits of the first ten million primes, then "9" occurs the least, followed by "1", then "3", with "7" occurring the most. [Gupta]