10011...10101 (37-digits)

This number is a prime.

                                    1001110 1110010111 0101001100 0111110101

The smallest concatenate prime comprising all hour numbers of an analogue clock in binary scale in an anticlockwise sweep (corresponds to the concatenation of base two representations of 4, 3, 2, 1, 12, 11, 10, 9, 8, 7, 6, 5 ). Note the prime number of digits. [Beedassy]