24

24 = 2*2*2*3

2²⁴ - 1 =  3 * 3 * 5 * 7 * 13 * 17 * 241

10²⁴ - 1 =  3 * 3 * 3 * 7 * 11 * 13 * 37 * 73 * 101 * 137 * 9901 * 99990001