GCF of 4 and 42 (Greatest Common Factor)

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

What is the Greatest Common Divisor of 4 and 42?

Answer

GCF of 4 and 42 is
2

(Two)

Finding GCF for 4 and 42 using all factors (divisors) listing

The first method to find GCF for numbers 4 and 42 is to list all factors for both numbers and pick the highest common one:

All factors of 4: 1, 2, 4

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

So the Greatest Common Factor for 4 and 42 is 2

Finding GCF for 4 and 42 by Prime Factorization

The second method to find GCF for numbers 4 and 42 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 4: 2, 2

All Prime Factors of 42: 2, 3, 7

As we can see there is only one Prime Factor common to both numbers. It is 2

So 2 is the Greatest Common Factor of 4 and 42

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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 4 and 42? (The answer is: 2). Select the first number (e.g. '4') 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.
"Greatest Common Factor" Calculator

Greatest Common Factor of

and

GCF Table

Number 1Number 2GCF
4151
4164
4182
4204
4211
4231
4244
4251
4262
4271
4284
4302
4324
4351
4364
4371
4382
4404
4422
4444
4451
4484
4491
4502
4511
4524
4531
4564
4571
4604

FAQ

What is the Greatest Common Divisor of 4 and 42?

GCF of 4 and 42 is 2

How to find the GCF of 4 and 42?

You can find the GCF of 4 and 42 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 4 and 42 is 2.

What prime factors do 4 and 42 share?

The prime factorizations of 4 and 42 have 2 in common, and multiplying those shared primes gives 2 — exactly the greatest common factor.

How does the GCF reduce the fraction 4/42?

Divide the numerator and the denominator by the GCF 2: 4 ÷ 2 = 2 and 42 ÷ 2 = 21. So 4/42 in lowest terms is 2/21.

See Also