base 27 is a positional numeral system with twenty-seven as its base. It uses 27 different digits for representing numbers. The digits for base 27 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, and q.
hexadecimal (base 16)
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).