GCF for 28 and 56

What is the Greatest common Divisor of 28 and 56?

Answer: GCF of 28 and 56 is 28

(Twenty-eight)

Finding GCF for 28 and 56 using all factors (divisors) listing

The first method to find GCF for numbers 28 and 56 is to list all factors for both numbers and pick the highest common one:

All factors of 28: 1, 2, 4, 7, 14, 28

All factors of 56: 1, 2, 4, 7, 8, 14, 28, 56

So the Greatest Common Factor for 28 and 56 is 28

Finding GCF for 28 and 56 by Prime Factorization

The second method to find GCF for numbers 28 and 56 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 28: 2, 2, 7

All Prime Factors of 56: 2, 2, 2, 7

As we can see there are Prime Factors common to both numbers: 2, 2, 7

Now we need to multiply them to find GCF: 2 × 2 × 7 = 28

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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 28 and 56? (The answer is: 28). Select the first number (e.g. '28') and the second number (e.g. '56'). 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

GCF Table

Number 1Number 2GCF
1356
1456
15561
1656
17561
1856
19561
2056
2156
22562
23561
2456
25561
26562
27561
2856
29561
3056
31561
3256
33561
3456
3556
3656
37561
38562
3956
4056
41561
4256

FAQ

What is the Greatest common Divisor of 28 and 56?

GCF of 28 and 56 is 28