Least Common Multiple of 20 and 31

Created By : Jatin Gogia

Reviewed By : Rajasekhar Valipishetty

Last Updated : Apr 06, 2023


Free LCM Calculator determines the least common multiple (LCM) between 20 and 31 the smallest integer that is 620 that is divisible by both numbers.

Least Common Multiple (LCM) of 20 and 31 is 620.

LCM(20,31) = 620

LCM of 20 and 31

Least common multiple or lowest common denominator (LCD) can be calculated in three ways;

LCM of:
and

Least Common Multiple of 20 and 31

LCM of 20 and 31 is 620

Least common multiple can be found by multiplying the highest exponent prime factors of 20 and 31. First we will calculate the prime factors of 20 and 31.

Prime Factorization of 20


2 20
2 10
5 5
1

Prime factors of 20 are 2,5. Prime factorization of 20 in exponential form is:

20 = 22×51

Prime Factorization of 31


31 31
1

Prime factors of 31 are 31. Prime factorization of 31 in exponential form is:

31 = 311

Now multiplying the highest exponent prime factors to calculate the LCM of 20 and 31.

LCM(20,31) = 22×51×311
LCM(20,31) = 620

Factors of 20

List of positive integer factors of 20 that divides 20 without a remainder.

1, 2, 4, 5, 10, 20

Factors of 31

List of positive integer factors of 31 that divides 31 without a remainder.

1, 31

Least Common Multiple of 20 and 31 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 20 and 31, than apply into the LCM equation.

GCF(20,31) = 1
LCM(20,31) = ( 20 × 31) / 1
LCM(20,31) = 620 / 1
LCM(20,31) = 620

Properties of LCM 20 and 31

(i) The LCM of 31 and 20 is associative

LCM of 20 and 31 = LCM of 31 and 20

Frequently Asked Questions on LCM of 20 and 31

1. What is the LCM of 20 and 31?

Answer: LCM of 20 and 31 is 620.

2. What are the Factors of 20?

Answer: Factors of 20 are 1, 2, 4, 5, 10, 20. There are 6 integers that are factors of 20. The greatest factor of 20 is 20.

3. What are the Factors of 31?

Answer: Factors of 31 are 1, 31. There are 2 integers that are factors of 31. The greatest factor of 31 is 31.

4. How to Find the LCM of 20 and 31?

Answer:

Least Common Multiple of 20 and 31 = 620

Step 1: Find the prime factorization of 20

20 = 2 x 2 x 5

Step 2: Find the prime factorization of 31

31 = 31

Step 3: Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:

LCM = 620 = 2 x 2 x 5 x 31

Step 4: Therefore, the least common multiple of 20 and 31 is 620.