409,457 = 71 x 73 x 79
Assuming you mean exactly 8, any that are composed of:Three different prime numbers, eg 30 = 2 x 3 x 5, 42 = 2 x 3 x 7, 409457 = 71 x 73 x 79Two different primes, one cubed (to the power 3), eg 24 = 23 x 3, 56 = 23 x 7, 1102267 = 313 x 37One prime to the power 7, eg 128 = 27, 2187 = 37, 893871739 = 197A number having more than 8 factors also has 8 factors (plus some). eg 36 has 8 factors (plus another 1), 90 has 8 factors (plus another 4)