GCF and LCM Calculator Logo

What is the Least Common Multiple of 1265 and 1280?

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 1265 and 1280 is 323840.

LCM(1265,1280) = 323840

LCM Calculator and
and

Least Common Multiple of 1265 and 1280 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 1265 and 1280, than apply into the LCM equation.

GCF(1265,1280) = 5
LCM(1265,1280) = ( 1265 × 1280) / 5
LCM(1265,1280) = 1619200 / 5
LCM(1265,1280) = 323840

Least Common Multiple (LCM) of 1265 and 1280 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 1265 and 1280. First we will calculate the prime factors of 1265 and 1280.

Prime Factorization of 1265

Prime factors of 1265 are 5, 11, 23. Prime factorization of 1265 in exponential form is:

1265 = 51 × 111 × 231

Prime Factorization of 1280

Prime factors of 1280 are 2, 5. Prime factorization of 1280 in exponential form is:

1280 = 28 × 51

Now multiplying the highest exponent prime factors to calculate the LCM of 1265 and 1280.

LCM(1265,1280) = 51 × 111 × 231 × 28
LCM(1265,1280) = 323840