37 is a factor of all 3-digit repdigits (a repdigit is a number composed of repeated instances of the same digit) due to: 37 * 3 = 111
111 * 2 = 222
111 * 3 = 333
...
111 * 9 = 999
So:
37 * 3 = 111
37 * 6 = 37 * (3 * 2) = (37 * 3) * 2 = 111 * 2 = 222
37 * 9 = 37 * (3 * 3) = (37 * 3) * 3 = 111 * 3 = 333
37 * 12 = 37 * (3 * 4) = (37 * 3) * 4 = 111 * 4 = 444
...
37 * 27 = 37 * (3 * 9) = (37 * 3) * 9 = 111 * 9 = 999