59142...76857 (46-digits)

This number is a prime.

                          591423 2143423142 5345234567 4657564765 4758676857

The larger of only two primes made up from a double-digit prime, (59), followed from the concatenation of primes, each consisting of four successive digits from the sets of digits: (a) (1, 2, 3, 4), (b) (2, 3, 4, 5), (c) (4, 5, 6, 7), (d) (5, 6, 7, 8), i.e., 1423, 2143, 4231, 4253, 4523, 4567, 4657, 5647, 6547, 5867, 6857. [Loungrides]