GCF for 21 and 100

What is the Greatest common Divisor of 21 and 100?

Answer: GCF of 21 and 100 is 1

(One)

Finding GCF for 21 and 100 using all factors (divisors) listing

The first method to find GCF for numbers 21 and 100 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 100: 1, 2, 4, 5, 10, 20, 25, 50, 100

So the Greatest Common Factor for 21 and 100 is 1

Finding GCF for 21 and 100 by Prime Factorization

GCF Table

Number 1Number 2GCF
6100
7100
8100
9100
10100
111001
12100
131001
141002
15100
16100
171001
18100
191001
20100
21100
22100
231001
24100
25100
261002
27100
28100
291001
30100
311001
32100
331001
341002
35100

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 21 and 100? (The answer is: 1). Select the first number (e.g. '21') and the second number (e.g. '100'). 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 21 and 100?

GCF of 21 and 100 is 1