What is the Least Common Multiple of 1280 and 1289?

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 1280 and 1289 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 1280 and 1289, than apply into the LCM equation.

GCF(1280,1289) = 1
LCM(1280,1289) = ( 1280 × 1289) / 1
LCM(1280,1289) = 1649920 / 1
LCM(1280,1289) = 1649920

Least Common Multiple (LCM) of 1280 and 1289 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 1280 and 1289. First we will calculate the prime factors of 1280 and 1289.

Prime Factorization of 1280

Prime Factorization of 1289

Now multiplying the highest exponent prime factors to calculate the LCM of 1280 and 1289.

LCM(1280,1289) = 2⁸ × 5¹ × 1289¹
LCM(1280,1289) = 1649920