HumbleGenerator[max_] := Sort[Flatten@ParallelTable[ 2^i 3^j 5^k 7^m, {i, 0, Log[2, max]}, {j, 0, Log[3, max/2^i]}, {k, 0, Log[5, max/(2^i 3^j)]}, {m, 0, Log[7, max/(2^i 3^j 5^k)]}]] {"First 50 Humble Numbers:", HumbleGenerator[120], "\nDigits\[Rule]Count", Rule @@@ Tally[IntegerLength /@ Drop[HumbleGenerator[10^100], -1]] // Column} // Column