The vigesimal or base 20 numeral system is based on twenty (in the same way in which the decimal numeral system is based on ten).
base 22
base 22 is a positional numeral system with twenty-two as its base. It uses 22 different digits for representing numbers. The digits for base 22 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, and l.