18910...61109 (32-digits)

This number is a prime.

                                         18 9106911896 0619189609 1118961109

The smallest invertible prime containing all the invertible digits, formed from the concatenation of four invertible primes each containing all invertible digits, i.e., {18910691, 18960619, 18960911, 18961109}. [Bajpai]