1373

This number is a prime.

+ The five 2 or 3-digit strings contained in 1373 are prime. It is the smallest 4-digit prime with this property. [Mix]

+ The smallest prime formed by concatenating two double-digit emirps (13, 73). Note that 3137, formed from their reversals, is also prime. [Loungrides]

+ The smallest prime formed by inserting an emirp between the digits of another emirp. [Loungrides]

(There are 3 curios for this number that have not yet been approved by an editor.)

Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell