GCF (HCF) of 17 and 21

"Greatest Common Factor" Calculator

What is the Greatest Common Divisor of 17 and 21?

Answer

GCF (HCF) of 17 and 21 is

Common factors: 1

Only 1 divides both: 17 and 21 share no prime factor.

Such numbers are called coprime (relatively prime); their LCM is just the product: 17 × 21 = 357.

17 — prime

21 = 3 × 7

Prime	17	21	Lowest power
3	—	3	—
7	—	7	—
17	17	—	—

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

GCF = 1

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Related Calculations

GCF Table

Number 1	Number 2	GCF
17	18	1
17	19	1
17	20	1
17	21	1
17	23	1
17	24	1
17	25	1
17	26	1
17	27	1
17	28	1
17	29	1
17	30	1
17	34	17
17	38	1
17	41	1
17	42	1
17	43	1
17	44	1
17	46	1
17	47	1
17	48	1
17	51	17
17	54	1
17	55	1
17	56	1
17	58	1
17	60	1

FAQ

What is the Greatest Common Divisor of 17 and 21?

GCF (HCF) of 17 and 21 is 1

How to find the GCF of 17 and 21?

You can find the GCF of 17 and 21 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 17 and 21 is 1.

What prime factors do 17 and 21 share?

17 and 21 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 17/21?

Divide the numerator and the denominator by the GCF 1: 17 ÷ 1 = 17 and 21 ÷ 1 = 21. So 17/21 in lowest terms is 17/21.

Are 17 and 21 coprime?

Yes, 17 and 21 are coprime (relatively prime) because their Greatest Common Factor is 1.

GCF (HCF) of 17 and 21

What is the Greatest Common Divisor of 17 and 21?

More with these numbers

Related Calculations

See Also

GCF Table

FAQ

What is the Greatest Common Divisor of 17 and 21?

How to find the GCF of 17 and 21?

What prime factors do 17 and 21 share?

How does the GCF reduce the fraction 17/21?

Are 17 and 21 coprime?

See Also

Number 1	Number 2	GCF
17	18	1
17	19	1
17	20	1
17	21	1
17	23	1
17	24	1
17	25	1
17	26	1
17	27	1
17	28	1
17	29	1
17	30	1
17	34	17
17	38	1
17	41	1
17	42	1
17	43	1
17	44	1
17	46	1
17	47	1
17	48	1
17	51	17
17	54	1
17	55	1
17	56	1
17	58	1
17	60	1

Number 1	Number 2	GCF
17	18	1
17	19	1
17	20	1
17	21	1
17	23	1
17	24	1
17	25	1
17	26	1
17	27	1
17	28	1
17	29	1
17	30	1
17	34	17
17	38	1
17	41	1
17	42	1
17	43	1
17	44	1
17	46	1
17	47	1
17	48	1
17	51	17
17	54	1
17	55	1
17	56	1
17	58	1
17	60	1

Number 1	Number 2	GCF
17	18	1
17	19	1
17	20	1
17	21	1
17	23	1
17	24	1
17	25	1
17	26	1
17	27	1
17	28	1
17	29	1
17	30	1
17	34	17
17	38	1
17	41	1
17	42	1
17	43	1
17	44	1
17	46	1
17	47	1
17	48	1
17	51	17
17	54	1
17	55	1
17	56	1
17	58	1
17	60	1