1379

This number is a composite.

1379 is a primeval number. The 31 primes (from 3 to 9371) are the most that can be created from a 4-digit number. Note that 31 is a lucky number and the first four terms of the lucky numbers sequence are 1, 3, 7, 9. [Homewood]

"1379" has never been found in the sequence 2, 23, 235, 2357, 12357, 3, ... .

By imbedding an ergodic Markov chain in the phenomenon of prime numbers, one can give odds that the next prime ends in 1, 3, 7 or 9. [Uppuluri]