31374...31137 (54-digits)

This number is a prime.

                 3137 4143475359 6167717379 8389971011 0310710911 3127131137

The smallest prime formed by concatenation of 23 consecutive primes (31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137). [Gupta]