What is the Greatest Common Factor of 3990 and 3999?

Greatest common factor (GCF) of 3990 and 3999 is 3.

GCF(3990,3999) = 3

We will now calculate the prime factors of 3990 and 3999, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 3990 and 3999.

How to find the GCF of 3990 and 3999?

We will first find the prime factorization of 3990 and 3999. After we will calculate the factors of 3990 and 3999 and find the biggest common factor number .

Step-1: Prime Factorization of 3990

Prime factors of 3990 are 2, 3, 5, 7, 19. Prime factorization of 3990 in exponential form is:

3990 = 2¹ × 3¹ × 5¹ × 7¹ × 19¹

Step-2: Prime Factorization of 3999

Prime factors of 3999 are 3, 31, 43. Prime factorization of 3999 in exponential form is:

3999 = 3¹ × 31¹ × 43¹

Step-3: Factors of 3990

List of positive integer factors of 3990 that divides 3990 without a remainder.

1, 2, 3, 5, 6, 7, 10, 14, 15, 19, 21, 30, 35, 38, 42, 57, 70, 95, 105, 114, 133, 190, 210, 266, 285, 399, 570, 665, 798, 1330, 1995

Step-4: Factors of 3999

List of positive integer factors of 3999 that divides 3990 without a remainder.

1, 3, 31, 43, 93, 129, 1333

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 3990 and 3999. The biggest common factor number is the GCF number.
So the greatest common factor 3990 and 3999 is 3.

Also check out the Least Common Multiple of 3990 and 3999