Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 820, 821 i.e. 1 largest integer by which both the numbers can be divided.
Greatest common factor (GCF) of 820 and 821 is 1.
GCF(820,821) = 1
Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;
Prime Factorization of 820
2 | 820 |
2 | 410 |
5 | 205 |
41 | 41 |
1 |
Prime factors of 820 are 2,5,41. Prime factorization of 820 in exponential form is:
820 = 22×51×411
Prime Factorization of 821
821 | 821 |
1 |
Prime factors of 821 are 821. Prime factorization of 821 in exponential form is:
821 = 8211
∴ So by taking common prime factors GCF of 820 and 821 is 1
Factors of 820
List of positive integer factors of 820 that divides 820 without a remainder.
1,2,4,5,10,20,41,82,164,205,410,820
Factors of 821
List of positive integer factors of 821 that divides 821 without a remainder.
1,821
Greatest Common Factor
We found the factors and prime factorization of 820 and 821. The biggest common factor number is the GCF number.
So the greatest common factor 820 and 821 is 1.
Also check out the Least Common Multiple of 820 and 821
(i) The GCF of 820 and 821 is associative
GCF of 820 and 821 = GCF of 821 and 820
1. What is the GCF of 820 and 821?
Answer: GCF of 820 and 821 is 1.
2. What are the Factors of 820?
Answer: Factors of 820 are 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410, 820. There are 12 integers that are factors of 820. The greatest factor of 820 is 820.
3. What are the Factors of 821?
Answer: Factors of 821 are 1, 821. There are 2 integers that are factors of 821. The greatest factor of 821 is 821.
4. How to Find the GCF of 820 and 821?
Answer:
Greatest Common Factor of 820 and 821 = 1
Step 1: Find the prime factorization of 820
820 = 2 x 2 x 5 x 41
Step 2: Find the prime factorization of 821
821 = 821
Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:
GCF = = 1
Step 4: Therefore, the greatest common factor of 820 and 821 is 1