9

This number is a composite.

Single Curio View: (Seek other curios for this number)

The smallest composite number whose both concatenations with its home prime, (i.e., 311), in order and reverse order, 9311 and 3119 are primes. [Loungrides]

Submitted: 2020-09-26 17:45:39; Last Modified: 2020-09-30 11:37:59.