GCF for 80 and 840

What is the Greatest Common Factor of 80 and 840?

Answer: GCF of 80 and 840 is 40

(Forty)

Finding GCF for 80 and 840 using all factors (divisors) listing

The first method to find GCF for numbers 80 and 840 is to list all factors for both numbers and pick the highest common one:

All factors of 80: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

All factors of 840: 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, 840

So the Greatest Common Factor for 80 and 840 is 40

Finding GCF for 80 and 840 by Prime Factorization

The second method to find GCF for numbers 80 and 840 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 80: 2, 2, 2, 2, 5

All Prime Factors of 840: 2, 2, 2, 3, 5, 7

As we can see there are Prime Factors common to both numbers: 2, 2, 2, 5

Now we need to multiply them to find GCF: 2 × 2 × 2 × 5 = 40

GCF Table

Number 1Number 2GCF
658405
668406
678401
688404
698403
7084070
718401
7284024
738401
748402
7584015
768404
778407
788406
798401
8084040
818403
828402
838401
8484084
858405
868402
878403
888408
898401
9084030
918407
928404
938403
948402

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest Common Factor of 80 and 840? (The answer is: 40). Select the first number (e.g. '80') and the second number (e.g. '840'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest Common Factor of 80 and 840?

GCF of 80 and 840 is 40