The duodecimal system (also known as base 12 or dozenal) is a positional notation numeral system using twelve as its base.
base 17
base 17 is a positional numeral system with seventeen as its base. It uses 17 different digits for representing numbers. The digits for base 17 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, and g.