15121

This number is a prime.

The smallest strobogrammatic prime with the most topologically-equivalent distinct digits as displayed on 7-segment calculator. [Note that on calculator display, the three groups of topologically-equivalent digits are (1, 2, 5, 7) ; (3, 4) ; (6, 9) ] [Beedassy]

The smallest non-palindromic prime such that symmetrically about the vertical. [Marcel]