Word size of most modern cpu’s is 32 or 64 bits. Both are a power of 2.
This looks “intuitively reasonable”, because a bit has 2 states, but I don’t actually have a hard argument for why this is the case. Moreover, in the past, word sizes of processors have been multiples of other numbers, such as multiples of 6 (because characters were encoded in 6 bits).
What is the reason that chip designers have chosen to make word sizes a multiple of 2?