What is the Greatest Common Factor of 3840 and 3855?

Greatest common factor (GCF) of 3840 and 3855 is 15.

GCF(3840,3855) = 15

We will now calculate the prime factors of 3840 and 3855, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 3840 and 3855.

How to find the GCF of 3840 and 3855?

We will first find the prime factorization of 3840 and 3855. After we will calculate the factors of 3840 and 3855 and find the biggest common factor number .

Step-1: Prime Factorization of 3840

Prime factors of 3840 are 2, 3, 5. Prime factorization of 3840 in exponential form is:

3840 = 2⁸ × 3¹ × 5¹

Step-2: Prime Factorization of 3855

Prime factors of 3855 are 3, 5, 257. Prime factorization of 3855 in exponential form is:

3855 = 3¹ × 5¹ × 257¹

Step-3: Factors of 3840

List of positive integer factors of 3840 that divides 3840 without a remainder.

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920

Step-4: Factors of 3855

List of positive integer factors of 3855 that divides 3840 without a remainder.

1, 3, 5, 15, 257, 771, 1285

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 3840 and 3855. The biggest common factor number is the GCF number.
So the greatest common factor 3840 and 3855 is 15.

Also check out the Least Common Multiple of 3840 and 3855