Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Free LCM Calculator determines the least common multiple (LCM) between 21 and 22 the smallest integer that is 462 that is divisible by both numbers.
Least Common Multiple (LCM) of 21 and 22 is 462.
LCM(21,22) = 462
Least common multiple or lowest common denominator (LCD) can be calculated in three ways;
Least common multiple can be found by multiplying the highest exponent prime factors of 21 and 22. First we will calculate the prime factors of 21 and 22.
Prime Factorization of 21
3 | 21 |
7 | 7 |
1 |
Prime factors of 21 are 3,7. Prime factorization of 21 in exponential form is:
21 = 31×71
Prime Factorization of 22
2 | 22 |
11 | 11 |
1 |
Prime factors of 22 are 2,11. Prime factorization of 22 in exponential form is:
22 = 21×111
Now multiplying the highest exponent prime factors to calculate the LCM of 21 and 22.
LCM(21,22) = 21×31×71×111
LCM(21,22) = 462
Factors of 21
List of positive integer factors of 21 that divides 21 without a remainder.
1, 3, 7, 21
Factors of 22
List of positive integer factors of 22 that divides 22 without a remainder.
1, 2, 11, 22
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 21 and 22, than apply into the LCM equation.
GCF(21,22) = 1
LCM(21,22) = ( 21 × 22) / 1
LCM(21,22) = 462 / 1
LCM(21,22) = 462
(i) The LCM of 22 and 21 is associative
LCM of 21 and 22 = LCM of 22 and 21
1. What is the LCM of 21 and 22?
Answer: LCM of 21 and 22 is 462.
2. What are the Factors of 21?
Answer: Factors of 21 are 1, 3, 7, 21. There are 4 integers that are factors of 21. The greatest factor of 21 is 21.
3. What are the Factors of 22?
Answer: Factors of 22 are 1, 2, 11, 22. There are 4 integers that are factors of 22. The greatest factor of 22 is 22.
4. How to Find the LCM of 21 and 22?
Answer:
Least Common Multiple of 21 and 22 = 462
Step 1: Find the prime factorization of 21
21 = 3 x 7
Step 2: Find the prime factorization of 22
22 = 2 x 11
Step 3: Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:
LCM = 462 = 2 x 3 x 7 x 11
Step 4: Therefore, the least common multiple of 21 and 22 is 462.