GCF for 20 and 945

What is the Greatest Common Factor of 20 and 945?

Answer: GCF of 20 and 945 is 5

(Five)

Finding GCF for 20 and 945 using all factors (divisors) listing

The first method to find GCF for numbers 20 and 945 is to list all factors for both numbers and pick the highest common one:

All factors of 20: 1, 2, 4, 5, 10, 20

All factors of 945: 1, 3, 5, 7, 9, 15, 21, 27, 35, 45, 63, 105, 135, 189, 315, 945

So the Greatest Common Factor for 20 and 945 is 5

Finding GCF for 20 and 945 by Prime Factorization

The second method to find GCF for numbers 20 and 945 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 20: 2, 2, 5

All Prime Factors of 945: 3, 3, 3, 5, 7

As we can see there is only one Prime Factor common to both numbers. It is 5

So 5 is the Greatest Common Factor of 20 and 945

GCF Table

Number 1Number 2GCF
59455
69453
79457
89451
99459
109455
119451
129453
139451
149457
1594515
169451
179451
189459
199451
209455
2194521
229451
239451
249453
259455
269451
2794527
289457
299451
3094515
319451
329451
339453
349451

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 Factor of 20 and 945? (The answer is: 5). Select the first number (e.g. '20') and the second number (e.g. '945'). 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

FAQ

What is the Greatest Common Factor of 20 and 945?

GCF of 20 and 945 is 5