16001

This number is a prime.

The only prime (bemirp) p of the form p = a^b*c^d+1, where a, b, c, d are the prime digits, i.e., 2^7*5^3+1 = 16001. [Loungrides]

The smaller of only two 5-digit ZIP Codes that are bemirps. It belongs to Butler, PA. (You can find the other location by inverting 16001, then reading it backwards.)

The smallest bemirp de Polignac number. (A de Polygnac number is an odd number n that cannot be expressed as n = 2^k+p, where p is prime). [Loungrides]