What is the Greatest Common Factor of 20990 and 21000?

Greatest common factor (GCF) of 20990 and 21000 is 10.

GCF(20990,21000) = 10

We will now calculate the prime factors of 20990 and 21000, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20990 and 21000.

How to find the GCF of 20990 and 21000?

We will first find the prime factorization of 20990 and 21000. After we will calculate the factors of 20990 and 21000 and find the biggest common factor number .

Step-1: Prime Factorization of 20990

Prime factors of 20990 are 2, 5, 2099. Prime factorization of 20990 in exponential form is:

20990 = 2¹ × 5¹ × 2099¹

Step-2: Prime Factorization of 21000

Prime factors of 21000 are 2, 3, 5, 7. Prime factorization of 21000 in exponential form is:

21000 = 2³ × 3¹ × 5³ × 7¹

Step-3: Factors of 20990

List of positive integer factors of 20990 that divides 20990 without a remainder.

1, 2, 5, 10, 2099, 4198, 10495

Step-4: Factors of 21000

List of positive integer factors of 21000 that divides 20990 without a remainder.

1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 25, 28, 30, 35, 40, 42, 50, 56, 60, 70, 75, 84, 100, 105, 120, 125, 140, 150, 168, 175, 200, 210, 250, 280, 300, 350, 375, 420, 500, 525, 600, 700, 750, 840, 875, 1000, 1050, 1400, 1500, 1750, 2100, 2625, 3000, 3500, 4200, 5250, 7000, 10500

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20990 and 21000. The biggest common factor number is the GCF number.
So the greatest common factor 20990 and 21000 is 10.

Also check out the Least Common Multiple of 20990 and 21000