What is the Least Common Multiple of 20405 and 20420?

Least common multiple or lowest common denominator (lcd) can be calculated in two way; with the LCM formula calculation of greatest common factor (GCF), or multiplying the prime factors with the highest exponent factor.

Least Common Multiple of 20405 and 20420 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 20405 and 20420, than apply into the LCM equation.

GCF(20405,20420) = 5
LCM(20405,20420) = ( 20405 × 20420) / 5
LCM(20405,20420) = 416670100 / 5
LCM(20405,20420) = 83334020

Least Common Multiple (LCM) of 20405 and 20420 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 20405 and 20420. First we will calculate the prime factors of 20405 and 20420.

Prime Factorization of 20405

Prime Factorization of 20420

Now multiplying the highest exponent prime factors to calculate the LCM of 20405 and 20420.

LCM(20405,20420) = 5¹ × 7¹ × 11¹ × 53¹ × 2² × 1021¹
LCM(20405,20420) = 83334020