The ternary numeral system (also called base-3) has three as its base. Analogous to a bit, a ternary digit is a trit (trinary digit). One trit is equivalent to log23 (about 1.58496) bits of information.
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.