GCF (HCF) of 6 and 18

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What is the Greatest Common Divisor of 6 and 18?

Answer

GCF (HCF) of 6 and 18 is
6

Common factors: 1, 2, 3, 6

6 divides 18 (18 ÷ 6 = 3), so the GCF is the smaller number itself.

6 = 2 × 3

18 = 2 × 32

Prime618Lowest power
2222
33323

GCF = 2 × 3 = 6

See Also

FAQ

What is the Greatest Common Divisor of 6 and 18?

GCF (HCF) of 6 and 18 is 6

How to find the GCF of 6 and 18?

You can find the GCF of 6 and 18 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 6 and 18 is 6.

What prime factors do 6 and 18 share?

The prime factorizations of 6 and 18 have 2 × 3 in common, and multiplying those shared primes gives 6 — exactly the greatest common factor.

How does the GCF reduce the fraction 6/18?

Divide the numerator and the denominator by the GCF 6: 6 ÷ 6 = 1 and 18 ÷ 6 = 3. So 6/18 in lowest terms is 1/3.