GCF for 20 and 170

What is the Greatest common Divisor of 20 and 170?

Answer: GCF of 20 and 170 is 10

(Ten)

Finding GCF for 20 and 170 using all factors (divisors) listing

The first method to find GCF for numbers 20 and 170 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 170: 1, 2, 5, 10, 17, 34, 85, 170

So the Greatest Common Factor for 20 and 170 is 10

Finding GCF for 20 and 170 by Prime Factorization

The second method to find GCF for numbers 20 and 170 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 170: 2, 5, 17

As we can see there are Prime Factors common to both numbers: 2, 5

Now we need to multiply them to find GCF: 2 × 5 = 10

Related Calculations

GCF Table

Number 1Number 2GCF
51705
61702
71701
81702
91701
1017010
111701
121702
131701
141702
151705
161702
1717017
181702
191701
2017010
211701
221702
231701
241702
251705
261702
271701
281702
291701
30170
311701
321702
331701
3417034

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 170? (The answer is: 10). Select the first number (e.g. '20') and the second number (e.g. '170'). 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 170?

GCF of 20 and 170 is 10