11101...80881 (34-digits)

This number is a prime.

                                       1110 1181181811 0080011180 8111880881

The ordered concatenation of the first seven palindromic strobogrammatic primes, i.e., 11, 101, 181, 18181, 1008001, 1180811, 1880881, is also prime. Note that these are consisting of the digits 0, 1, 8 only. [Loungrides]