GCF of 42 and 86 (Greatest Common Factor)

"Greatest Common Factor" Calculator
Greatest Common Factor of
and

What is the Greatest Common Divisor of 42 and 86?

Answer

GCF of 42 and 86 is
2

(Two)

Finding GCF for 42 and 86 using all factors (divisors) listing

The first method to find GCF for numbers 42 and 86 is to list all factors for both numbers and pick the highest common one:

All factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

All factors of 86: 1, 2, 43, 86

So the Greatest Common Factor for 42 and 86 is 2

Finding GCF for 42 and 86 by Prime Factorization

The second method to find GCF for numbers 42 and 86 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 42: 2, 3, 7

All Prime Factors of 86: 2, 43

As we can see there is only one Prime Factor common to both numbers. It is 2

So 2 is the Greatest Common Factor of 42 and 86

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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 Divisor of 42 and 86? (The answer is: 2). Select the first number (e.g. '42') and the second number (e.g. '86'). 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.
"Greatest Common Factor" Calculator
Greatest Common Factor of
and

GCF Table

Number 1Number 2GCF
422814
42442
42453
42462
42486
42497
42502
42513
42522
42546
42551
425614
42573
42582
42591
42606
426321
42651
427014
42726
42802
428442
42862
42906
42966
429814
421002
4210521
4223121
42136521

FAQ

What is the Greatest Common Divisor of 42 and 86?

GCF of 42 and 86 is 2

How to find the GCF of 42 and 86?

You can find the GCF of 42 and 86 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 42 and 86 is 2.

What prime factors do 42 and 86 share?

The prime factorizations of 42 and 86 have 2 in common, and multiplying those shared primes gives 2 — exactly the greatest common factor.

How does the GCF reduce the fraction 42/86?

Divide the numerator and the denominator by the GCF 2: 42 ÷ 2 = 21 and 86 ÷ 2 = 43. So 42/86 in lowest terms is 21/43.

See Also