What is the Least Common Multiple of 28405 and 28420?

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 28405 and 28420 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 28405 and 28420, than apply into the LCM equation.

GCF(28405,28420) = 5
LCM(28405,28420) = ( 28405 × 28420) / 5
LCM(28405,28420) = 807270100 / 5
LCM(28405,28420) = 161454020

Least Common Multiple (LCM) of 28405 and 28420 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 28405 and 28420. First we will calculate the prime factors of 28405 and 28420.

Prime Factorization of 28405

Prime Factorization of 28420

Now multiplying the highest exponent prime factors to calculate the LCM of 28405 and 28420.

LCM(28405,28420) = 5¹ × 13¹ × 19¹ × 23¹ × 2² × 7² × 29¹
LCM(28405,28420) = 161454020