11010...10001 (39-digits)

This number is a prime.

                                  110100000 0101011111 1000101001 1001110001

110100000010101111110001010011001110001 is believed to be the smallest number that is prime in every base 2 through 10. [Dobb]

The smallest number that is prime for bases 2, 3, 4, 5, 6, 7, 8, 9 and 10. [Carmody and Alpern]