GCF of 55 and 77 (Greatest Common Factor)

"Greatest Common Factor" Calculator
Greatest Common Factor of
and

What is the Greatest Common Divisor of 55 and 77?

Answer

GCF of 55 and 77 is
11

(Eleven)

Finding GCF for 55 and 77 using all factors (divisors) listing

The first method to find GCF for numbers 55 and 77 is to list all factors for both numbers and pick the highest common one:

All factors of 55: 1, 5, 11, 55

All factors of 77: 1, 7, 11, 77

So the Greatest Common Factor for 55 and 77 is 11

Finding GCF for 55 and 77 by Prime Factorization

The second method to find GCF for numbers 55 and 77 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 55: 5, 11

All Prime Factors of 77: 7, 11

As we can see there is only one Prime Factor common to both numbers. It is 11

So 11 is the Greatest Common Factor of 55 and 77

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About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest Common Divisor of 55 and 77? (The answer is: 11). Select the first number (e.g. '55') and the second number (e.g. '77'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder.
"Greatest Common Factor" Calculator
Greatest Common Factor of
and

GCF Table

Number 1Number 2GCF
55621
55631
55641
55655
556611
55671
55681
55691
55705
55711
55721
55731
55741
55755
55761
557711
55781
55791
55805
55811
55821
55831
55841
55855
55861
55871
558811
55891
55905
55911

FAQ

What is the Greatest Common Divisor of 55 and 77?

GCF of 55 and 77 is 11

How to find the GCF of 55 and 77?

You can find the GCF of 55 and 77 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 55 and 77 is 11.

What prime factors do 55 and 77 share?

The prime factorizations of 55 and 77 have 11 in common, and multiplying those shared primes gives 11 — exactly the greatest common factor.

How does the GCF reduce the fraction 55/77?

Divide the numerator and the denominator by the GCF 11: 55 ÷ 11 = 5 and 77 ÷ 11 = 7. So 55/77 in lowest terms is 5/7.

See Also