base 31 is a positional numeral system with thirty-one as its base. It uses 31 different digits for representing numbers. The digits for base 31 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, q, r, s, t, and u.
decimal
The decimal numeral system (also called base-ten positional numeral system, and occasionally called denary) is the standard system for denoting integer and non-integer numbers. It has ten as its base.