Answer
The prime factorization of 64 is $$ 2 \times 2 \times 2 \times 2 \times 2 \times 2$$
or
$$2^6$$
Work Step by Step
Using the factor tree, you will find that $2,2,2,2,2, $ and $2$ are the prime numbers that multiply to $64$, or just $2$ multiplied $6$ times.
$$ 2 \times 2 \times 2 \times 2 \times 2 \times 2$$
or
$$2^6$$