11010...10001 (39-digits)

This number is a prime.

                                  110100000 0101011111 1000101001 1001110001

Just showing those entries submitted by 'Carmody': (Click here to show all)

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