39717...98317 (27-digits)

This number is a prime.

                                               3971783 2971415953 4771298317

This prime is formed from the concatenation in order of all the primes 397, 1783, 2971, 4159, 5347, 7129, 8317, that are also concatenated from two primes summed to a hundred, i.e., (3, 97), (17, 83), (29, 71), (41, 59), (53, 47), (71, 29), (83, 17). [Loungrides]