GCF (HCF) of 42 and 86

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What is the Greatest Common Divisor of 42 and 86?

Answer

GCF (HCF) of 42 and 86 is
2

Common factors: 1, 2

2 divides both: 42 ÷ 2 = 21, 86 ÷ 2 = 43 — and 21 and 43 share no factor but 1, so no larger number divides both.

42 = 2 × 3 × 7

86 = 2 × 43

Prime4286Lowest power
2222
33——
77——
43—43—

— = power 0: the prime is not a factor of this number, so it cannot be in the GCF.

GCF = 2

See Also

FAQ

What is the Greatest Common Divisor of 42 and 86?

GCF (HCF) 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.