What is the Least Common Multiple of 21905 and 21909?

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 21909 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 21909, than apply into the LCM equation.

GCF(21905,21909) = 1
LCM(21905,21909) = ( 21905 × 21909) / 1
LCM(21905,21909) = 479916645 / 1
LCM(21905,21909) = 479916645

Least Common Multiple (LCM) of 21905 and 21909 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 21905 and 21909. First we will calculate the prime factors of 21905 and 21909.

Prime Factorization of 21905

Prime Factorization of 21909

Now multiplying the highest exponent prime factors to calculate the LCM of 21905 and 21909.

LCM(21905,21909) = 5¹ × 13¹ × 337¹ × 3¹ × 67¹ × 109¹
LCM(21905,21909) = 479916645