GCF (HCF) of 5 and 28

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What is the Greatest Common Divisor of 5 and 28?

Answer

GCF (HCF) of 5 and 28 is
1

Common factors: 1

Only 1 divides both: 5 and 28 share no prime factor.

Such numbers are called coprime (relatively prime); their LCM is just the product: 5 × 28 = 140.

5 — prime

28 = 22 × 7

Prime528Lowest power
2—22—
55——
7—7—

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

GCF = 1

See Also

FAQ

What is the Greatest Common Divisor of 5 and 28?

GCF (HCF) of 5 and 28 is 1

How to find the GCF of 5 and 28?

You can find the GCF of 5 and 28 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 5 and 28 is 1.

What prime factors do 5 and 28 share?

5 and 28 have no prime factor in common, so the only integer that divides both of them is 1 and their GCF is 1.

How does the GCF reduce the fraction 5/28?

Divide the numerator and the denominator by the GCF 1: 5 ÷ 1 = 5 and 28 ÷ 1 = 28. So 5/28 in lowest terms is 5/28.

Are 5 and 28 coprime?

Yes, 5 and 28 are coprime (relatively prime) because their Greatest Common Factor is 1.