Question: what is the greatest common factor (gcf) of 64 and 12?
Answer: The prime factorization of 12 is: 2 x 2 x 3. The prime factors and multiplicities 64 and 12 have in common are: 2 x 2. 2 x 2 is the gcf of 64 and 12. gcf(64,12) = 4.