GCF (HCF) of 9 and 20

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Greatest Common Factor of
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What is the Greatest Common Divisor of 9 and 20?

Answer

GCF (HCF) of 9 and 20 is
1

Common factors: 1

Only 1 divides both: 9 and 20 share no prime factor.

Such numbers are called coprime (relatively prime); their LCM is just the product: 9 × 20 = 180.

9 = 32

20 = 22 × 5

Prime920Lowest power
2—22—
332——
5—5—

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

GCF = 1

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GCF Table

Number 1Number 2GCF
941
951
963
971
981
9101
9111
9123
9131
9141
9153
9161
9171
9189
9191
9201
9213
9221
9243
9251
9261
9279
9281
9291
9303
9321
9341
9351
9369
9393

FAQ

What is the Greatest Common Divisor of 9 and 20?

GCF (HCF) of 9 and 20 is 1

How to find the GCF of 9 and 20?

You can find the GCF of 9 and 20 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 9 and 20 is 1.

What prime factors do 9 and 20 share?

9 and 20 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 9/20?

Divide the numerator and the denominator by the GCF 1: 9 ÷ 1 = 9 and 20 ÷ 1 = 20. So 9/20 in lowest terms is 9/20.

Are 9 and 20 coprime?

Yes, 9 and 20 are coprime (relatively prime) because their Greatest Common Factor is 1.

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