What is the Greatest Common Factor of 20685 and 20690?

Greatest common factor (GCF) of 20685 and 20690 is 5.

GCF(20685,20690) = 5

We will now calculate the prime factors of 20685 and 20690, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20685 and 20690.

How to find the GCF of 20685 and 20690?

We will first find the prime factorization of 20685 and 20690. After we will calculate the factors of 20685 and 20690 and find the biggest common factor number .

Step-1: Prime Factorization of 20685

Prime factors of 20685 are 3, 5, 7, 197. Prime factorization of 20685 in exponential form is:

20685 = 3¹ × 5¹ × 7¹ × 197¹

Step-2: Prime Factorization of 20690

Prime factors of 20690 are 2, 5, 2069. Prime factorization of 20690 in exponential form is:

20690 = 2¹ × 5¹ × 2069¹

Step-3: Factors of 20685

List of positive integer factors of 20685 that divides 20685 without a remainder.

1, 3, 5, 7, 15, 21, 35, 105, 197, 591, 985, 1379, 2955, 4137, 6895

Step-4: Factors of 20690

List of positive integer factors of 20690 that divides 20685 without a remainder.

1, 2, 5, 10, 2069, 4138, 10345

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20685 and 20690. The biggest common factor number is the GCF number.
So the greatest common factor 20685 and 20690 is 5.

Also check out the Least Common Multiple of 20685 and 20690