GCF for 20 and 155

What is the Greatest common Divisor of 20 and 155?

Answer: GCF of 20 and 155 is 5

(Five)

Finding GCF for 20 and 155 using all factors (divisors) listing

The first method to find GCF for numbers 20 and 155 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 155: 1, 5, 31, 155

So the Greatest Common Factor for 20 and 155 is 5

Finding GCF for 20 and 155 by Prime Factorization

The second method to find GCF for numbers 20 and 155 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 155: 5, 31

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 155

Related Calculations

GCF Table

Number 1Number 2GCF
51555
61551
71551
81551
91551
101555
111551
121551
131551
141551
151555
161551
171551
181551
191551
201555
211551
221551
231551
241551
251555
261551
271551
281551
291551
301555
3115531
321551
331551
341551

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 20 and 155? (The answer is: 5). Select the first number (e.g. '20') and the second number (e.g. '155'). 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 Divisor of 20 and 155?

GCF of 20 and 155 is 5