974383618913296759

This number is a prime.

                                                         97438361 8913296759

The largest prime concatenated from nine distinct double-digit primes, so that deleting from the right each time a double-digit prime, always remains a prime, i.e., 974383618913296759, 9743836189132967, ..., 974383, 9743, 97. [Loungrides]