What is the Greatest Common Factor of 840 and 851?

Greatest common factor (GCF) of 840 and 851 is 1.

GCF(840,851) = 1

We will now calculate the prime factors of 840 and 851, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 840 and 851.

How to find the GCF of 840 and 851?

We will first find the prime factorization of 840 and 851. After we will calculate the factors of 840 and 851 and find the biggest common factor number .

Step-1: Prime Factorization of 840

Prime factors of 840 are 2, 3, 5, 7. Prime factorization of 840 in exponential form is:

840 = 2³ × 3¹ × 5¹ × 7¹

Step-2: Prime Factorization of 851

Prime factors of 851 are 23, 37. Prime factorization of 851 in exponential form is:

851 = 23¹ × 37¹

Step-3: Factors of 840

List of positive integer factors of 840 that divides 840 without a remainder.

1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420

Step-4: Factors of 851

List of positive integer factors of 851 that divides 840 without a remainder.

1, 23, 37

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 840 and 851. The biggest common factor number is the GCF number.
So the greatest common factor 840 and 851 is 1.

Also check out the Least Common Multiple of 840 and 851