What is the Greatest Common Factor of 3991 and 4004?

Greatest common factor (GCF) of 3991 and 4004 is 13.

GCF(3991,4004) = 13

We will now calculate the prime factors of 3991 and 4004, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 3991 and 4004.

How to find the GCF of 3991 and 4004?

We will first find the prime factorization of 3991 and 4004. After we will calculate the factors of 3991 and 4004 and find the biggest common factor number .

Step-1: Prime Factorization of 3991

Prime factors of 3991 are 13, 307. Prime factorization of 3991 in exponential form is:

3991 = 13¹ × 307¹

Step-2: Prime Factorization of 4004

Prime factors of 4004 are 2, 7, 11, 13. Prime factorization of 4004 in exponential form is:

4004 = 2² × 7¹ × 11¹ × 13¹

Step-3: Factors of 3991

List of positive integer factors of 3991 that divides 3991 without a remainder.

1, 13, 307

Step-4: Factors of 4004

List of positive integer factors of 4004 that divides 3991 without a remainder.

1, 2, 4, 7, 11, 13, 14, 22, 26, 28, 44, 52, 77, 91, 143, 154, 182, 286, 308, 364, 572, 1001, 2002

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 3991 and 4004. The biggest common factor number is the GCF number.
So the greatest common factor 3991 and 4004 is 13.

Also check out the Least Common Multiple of 3991 and 4004