GCF for 63 and 42

What is the Greatest common Divisor of 63 and 42?

Answer: GCF of 63 and 42 is 21

(Twenty-one)

Finding GCF for 63 and 42 using all factors (divisors) listing

The first method to find GCF for numbers 63 and 42 is to list all factors for both numbers and pick the highest common one:

All factors of 63: 1, 3, 7, 9, 21, 63

All factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

So the Greatest Common Factor for 63 and 42 is 21

Finding GCF for 63 and 42 by Prime Factorization

The second method to find GCF for numbers 63 and 42 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 63: 3, 3, 7

All Prime Factors of 42: 2, 3, 7

As we can see there are Prime Factors common to both numbers: 3, 7

Now we need to multiply them to find GCF: 3 × 7 = 21

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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 63 and 42? (The answer is: 21). Select the first number (e.g. '63') and the second number (e.g. '42'). 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
48426
49427
50422
51423
52422
53421
54426
55421
564214
57423
58422
59421
60426
61421
62422
6342
64422
65421
66426
67421
68422
69423
704214
71421
72426
73421
74422
75423
76422
77427

FAQ

What is the Greatest common Divisor of 63 and 42?

GCF of 63 and 42 is 21