Question: what is the greatest common factor of the numbers 16 and 28?
Answer: Greatest Common Factor of 16 and 28. Greatest common factor (GCF) of 16 and 28 is 4. We will now calculate the prime factors of 16 and 28, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 16 and 28.