GCF for 21 and 85

What is the Greatest Common Factor of 21 and 85?

Answer: GCF of 21 and 85 is 1

(One)

Finding GCF for 21 and 85 using all factors (divisors) listing

The first method to find GCF for numbers 21 and 85 is to list all factors for both numbers and pick the highest common one:

All factors of 21: 1, 3, 7, 21

All factors of 85: 1, 5, 17, 85

So the Greatest Common Factor for 21 and 85 is 1

Finding GCF for 21 and 85 by Prime Factorization

GCF Table

Number 1Number 2GCF
6851
7851
8851
9851
10855
11851
12851
13851
14851
15855
16851
1785
18851
19851
2085
21851
22851
23851
24851
25855
26851
27851
28851
29851
30855
31851
32851
33851
3485
35855

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 21 and 85? (The answer is: 1). Select the first number (e.g. '21') and the second number (e.g. '85'). 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 21 and 85?

GCF of 21 and 85 is 1