GCF for 21 and 140
"Greatest Common Factor" Calculator
What is the Greatest common Divisor of 21 and 140?
Answer: GCF of 21 and 140 is 7
(Seven)
Finding GCF for 21 and 140 using all factors (divisors) listing
The first method to find GCF for numbers 21 and 140 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 140: 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140
So the Greatest Common Factor for 21 and 140 is 7
Finding GCF for 21 and 140 by Prime Factorization
The second method to find GCF for numbers 21 and 140 is to list all Prime Factors for both numbers and multiply the common ones:
All Prime Factors of 21: 3, 7
All Prime Factors of 140: 2, 2, 5, 7
As we can see there is only one Prime Factor common to both numbers. It is 7
So 7 is the Greatest Common Factor of 21 and 140
See Also
- Least Common Multiple - Find the Least Common Multiple (LCM) of two numbers
Share This Calculation
Print
<a href="https://calculat.io/en/number/greatest-common-factor-of/21--140">What is the GCF of 21 and 140 - Calculatio</a>
GCF Table
| Number 1 | Number 2 | GCF |
|---|---|---|
| 6 | 140 | 2 |
| 7 | 140 | 7 |
| 8 | 140 | 4 |
| 9 | 140 | 1 |
| 10 | 140 | 10 |
| 11 | 140 | 1 |
| 12 | 140 | 4 |
| 13 | 140 | 1 |
| 14 | 140 | 14 |
| 15 | 140 | 5 |
| 16 | 140 | 4 |
| 17 | 140 | 1 |
| 18 | 140 | 2 |
| 19 | 140 | 1 |
| 20 | 140 | 20 |
| 21 | 140 | 7 |
| 22 | 140 | 2 |
| 23 | 140 | 1 |
| 24 | 140 | 4 |
| 25 | 140 | 5 |
| 26 | 140 | 2 |
| 27 | 140 | 1 |
| 28 | 140 | 28 |
| 29 | 140 | 1 |
| 30 | 140 | 10 |
| 31 | 140 | 1 |
| 32 | 140 | 4 |
| 33 | 140 | 1 |
| 34 | 140 | 2 |
| 35 | 140 | 35 |
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 140? (The answer is: 7). Select the first number (e.g. '21') and the second number (e.g. '140'). 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