What is the Least Common Multiple of 21905 and 21920?

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 21905 and 21920 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 21905 and 21920, than apply into the LCM equation.

GCF(21905,21920) = 5
LCM(21905,21920) = ( 21905 × 21920) / 5
LCM(21905,21920) = 480157600 / 5
LCM(21905,21920) = 96031520

Least Common Multiple (LCM) of 21905 and 21920 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 21905 and 21920. First we will calculate the prime factors of 21905 and 21920.

Prime Factorization of 21905

Prime Factorization of 21920

Now multiplying the highest exponent prime factors to calculate the LCM of 21905 and 21920.

LCM(21905,21920) = 5¹ × 13¹ × 337¹ × 2⁵ × 137¹
LCM(21905,21920) = 96031520