GCF for 28 and 40

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

What is the Greatest common Divisor of 28 and 40?

Answer: GCF of 28 and 40 is 4

(Four)

Finding GCF for 28 and 40 using all factors (divisors) listing

The first method to find GCF for numbers 28 and 40 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 40: 1, 2, 4, 5, 8, 10, 20, 40

So the Greatest Common Factor for 28 and 40 is 4

Finding GCF for 28 and 40 by Prime Factorization

The second method to find GCF for numbers 28 and 40 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 40: 2, 2, 2, 5

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

Now we need to multiply them to find GCF: 2 × 2 = 4

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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 40? (The answer is: 4). Select the first number (e.g. '28') and the second number (e.g. '40'). 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
13401
14402
15405
16408
17401
18402
19401
204020
21401
22402
23401
24408
25405
26402
27401
28404
29401
304010
31401
32408
33401
34402
35405
36404
37401
38402
39401
404040
41401
42402

FAQ

What is the Greatest common Divisor of 28 and 40?

GCF of 28 and 40 is 4

See Also