What is the Greatest Common Factor of 7905 and 7920?

Greatest common factor (GCF) of 7905 and 7920 is 15.

GCF(7905,7920) = 15

We will now calculate the prime factors of 7905 and 7920, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 7905 and 7920.

How to find the GCF of 7905 and 7920?

We will first find the prime factorization of 7905 and 7920. After we will calculate the factors of 7905 and 7920 and find the biggest common factor number .

Step-1: Prime Factorization of 7905

Prime factors of 7905 are 3, 5, 17, 31. Prime factorization of 7905 in exponential form is:

7905 = 3¹ × 5¹ × 17¹ × 31¹

Step-2: Prime Factorization of 7920

Prime factors of 7920 are 2, 3, 5, 11. Prime factorization of 7920 in exponential form is:

7920 = 2⁴ × 3² × 5¹ × 11¹

Step-3: Factors of 7905

List of positive integer factors of 7905 that divides 7905 without a remainder.

1, 3, 5, 15, 17, 31, 51, 85, 93, 155, 255, 465, 527, 1581, 2635

Step-4: Factors of 7920

List of positive integer factors of 7920 that divides 7905 without a remainder.

1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 15, 16, 18, 20, 22, 24, 30, 33, 36, 40, 44, 45, 48, 55, 60, 66, 72, 80, 88, 90, 99, 110, 120, 132, 144, 165, 176, 180, 198, 220, 240, 264, 330, 360, 396, 440, 495, 528, 660, 720, 792, 880, 990, 1320, 1584, 1980, 2640, 3960

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 7905 and 7920. The biggest common factor number is the GCF number.
So the greatest common factor 7905 and 7920 is 15.

Also check out the Least Common Multiple of 7905 and 7920