base 23 is a positional numeral system with twenty-three as its base. It uses 23 different digits for representing numbers. The digits for base 23 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, and m.

base 25 is a positional numeral system with twenty-five as its base. It uses 25 different digits for representing numbers. The digits for base 25 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, and o.