Earlier quoted context omitted.
Why would aliens work in base10?
Looks like they had 3 fingers per hand, so base 6 seems a likely choice. 6 works great as its divisible by 2 and 3. I wonder what base we would use if we (somehow) had a prime number of fingers. 2, 6, 30, 60?
2, 6, 12, 60, etc
Number of fingers doesn't matter, although you can shoehorn almost any base into them. For example, base 6 lets you count to 5 on one hand and use your other to coujt multiples of 6. This lets you count to 35 on two hands.
More info here: https://en.m.wikipedia.org/wiki/Superior_highly_composite_nu...