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What is the Least Common Multiple of 20405 and 20409?

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 (LCM) of 20405 and 20409 is 416445645.

LCM(20405,20409) = 416445645

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Least Common Multiple of 20405 and 20409 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 20409, than apply into the LCM equation.

GCF(20405,20409) = 1
LCM(20405,20409) = ( 20405 × 20409) / 1
LCM(20405,20409) = 416445645 / 1
LCM(20405,20409) = 416445645

Least Common Multiple (LCM) of 20405 and 20409 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 20405 and 20409. First we will calculate the prime factors of 20405 and 20409.

Prime Factorization of 20405

Prime factors of 20405 are 5, 7, 11, 53. Prime factorization of 20405 in exponential form is:

20405 = 51 × 71 × 111 × 531

Prime Factorization of 20409

Prime factors of 20409 are 3, 6803. Prime factorization of 20409 in exponential form is:

20409 = 31 × 68031

Now multiplying the highest exponent prime factors to calculate the LCM of 20405 and 20409.

LCM(20405,20409) = 51 × 71 × 111 × 531 × 31 × 68031
LCM(20405,20409) = 416445645