What is the Greatest Common Factor of 19605 and 19620?

Greatest common factor (GCF) of 19605 and 19620 is 15.

GCF(19605,19620) = 15

We will now calculate the prime factors of 19605 and 19620, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 19605 and 19620.

How to find the GCF of 19605 and 19620?

We will first find the prime factorization of 19605 and 19620. After we will calculate the factors of 19605 and 19620 and find the biggest common factor number .

Step-1: Prime Factorization of 19605

Prime factors of 19605 are 3, 5, 1307. Prime factorization of 19605 in exponential form is:

19605 = 3¹ × 5¹ × 1307¹

Step-2: Prime Factorization of 19620

Prime factors of 19620 are 2, 3, 5, 109. Prime factorization of 19620 in exponential form is:

19620 = 2² × 3² × 5¹ × 109¹

Step-3: Factors of 19605

List of positive integer factors of 19605 that divides 19605 without a remainder.

1, 3, 5, 15, 1307, 3921, 6535

Step-4: Factors of 19620

List of positive integer factors of 19620 that divides 19605 without a remainder.

1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90, 109, 180, 218, 327, 436, 545, 654, 981, 1090, 1308, 1635, 1962, 2180, 3270, 3924, 4905, 6540, 9810

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 19605 and 19620. The biggest common factor number is the GCF number.
So the greatest common factor 19605 and 19620 is 15.

Also check out the Least Common Multiple of 19605 and 19620