What is the Greatest Common Factor of 1815 and 1820?

Greatest common factor (GCF) of 1815 and 1820 is 5.

GCF(1815,1820) = 5

We will now calculate the prime factors of 1815 and 1820, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1815 and 1820.

How to find the GCF of 1815 and 1820?

We will first find the prime factorization of 1815 and 1820. After we will calculate the factors of 1815 and 1820 and find the biggest common factor number .

Step-1: Prime Factorization of 1815

Prime factors of 1815 are 3, 5, 11. Prime factorization of 1815 in exponential form is:

1815 = 3¹ × 5¹ × 11²

Step-2: Prime Factorization of 1820

Prime factors of 1820 are 2, 5, 7, 13. Prime factorization of 1820 in exponential form is:

1820 = 2² × 5¹ × 7¹ × 13¹

Step-3: Factors of 1815

List of positive integer factors of 1815 that divides 1815 without a remainder.

1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605

Step-4: Factors of 1820

List of positive integer factors of 1820 that divides 1815 without a remainder.

1, 2, 4, 5, 7, 10, 13, 14, 20, 26, 28, 35, 52, 65, 70, 91, 130, 140, 182, 260, 364, 455, 910

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1815 and 1820. The biggest common factor number is the GCF number.
So the greatest common factor 1815 and 1820 is 5.

Also check out the Least Common Multiple of 1815 and 1820