What is the Greatest Common Factor of 721 and 728?

Greatest common factor (GCF) of 721 and 728 is 7.

GCF(721,728) = 7

We will now calculate the prime factors of 721 and 728, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 721 and 728.

How to find the GCF of 721 and 728?

We will first find the prime factorization of 721 and 728. After we will calculate the factors of 721 and 728 and find the biggest common factor number .

Step-1: Prime Factorization of 721

Prime factors of 721 are 7, 103. Prime factorization of 721 in exponential form is:

721 = 7¹ × 103¹

Step-2: Prime Factorization of 728

Prime factors of 728 are 2, 7, 13. Prime factorization of 728 in exponential form is:

728 = 2³ × 7¹ × 13¹

Step-3: Factors of 721

List of positive integer factors of 721 that divides 721 without a remainder.

1, 7, 103

Step-4: Factors of 728

List of positive integer factors of 728 that divides 721 without a remainder.

1, 2, 4, 7, 8, 13, 14, 26, 28, 52, 56, 91, 104, 182, 364

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 721 and 728. The biggest common factor number is the GCF number.
So the greatest common factor 721 and 728 is 7.

Also check out the Least Common Multiple of 721 and 728