Question

What is the prime factor of 32

Answer 1

Use the factor tree 
      32
    4    8
  2*2  2*4
2*2   2*2*2
so the answer would be 2 to the fifth power 

Answer 2

We factor out primes from 32 to find it's prime factorization.

32=2*16=2*2*8=2*2*2*4=2*2*2*2*2.  2 is a prime number, so this cannot be reduced further.  Since we have five twos and no other primes, the factorization is 2^5, and the only prime factor is 2.