GCF for 20 and 145

What is the Greatest Common Factor of 20 and 145?

Answer: GCF of 20 and 145 is 5

(Five)

Finding GCF for 20 and 145 using all factors (divisors) listing

The first method to find GCF for numbers 20 and 145 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 145: 1, 5, 29, 145

So the Greatest Common Factor for 20 and 145 is 5

Finding GCF for 20 and 145 by Prime Factorization

The second method to find GCF for numbers 20 and 145 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 145: 5, 29

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 145

GCF Table

Number 1Number 2GCF
51455
61451
71451
81451
91451
101455
111451
121451
131451
141451
151455
161451
171451
181451
191451
201455
211451
221451
231451
241451
251455
261451
271451
281451
2914529
301455
311451
321451
331451
341451

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 145? (The answer is: 5). Select the first number (e.g. '20') and the second number (e.g. '145'). 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 145?

GCF of 20 and 145 is 5