39999...62731 (118-digits)

This number is a prime.

                        39999889 9993489445 3222147356 5546713568 1172082607
7931520423 2452113850 0132476717 9248444034 5910986805 6739255739 1849262731

Sequence of primes growing from the center, two digits each time from 00 to 99, no repetitions allowed. This example starts with a prime seed of "31": 31, 3931, 399731, 39992731, etc. [Rivera]