base 14 is a positional numeral system with fourteen as its base. It uses 14 different digits for representing numbers. The digits for base 14 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, and d.

base 21 is a positional numeral system with twenty-one as its base. It uses 21 different digits for representing numbers. The digits for base 21 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, and k.