[gvkjyyui] Base 6

Consider base 6.  Testing divisibility by 2 and 3 can be done by examining the last digit.  Similarly, decimal (hexal hexary) expansions of fractions with those denominators​ terminate.  Testing divisibility for 5 and 7 can be done by methods​ analogous to 9 and 11 in decimal.

6 = 3! might be useful.  Number of faces of a cube.

Previously, base 30.

Inspired by, the fingers on one hand can specify one digit in base 6.  Though finger counting is unary.