Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Free LCM Calculator determines the least common multiple (LCM) between 123 and 128 the smallest integer that is 15744 that is divisible by both numbers.
Least Common Multiple (LCM) of 123 and 128 is 15744.
LCM(123,128) = 15744
Least common multiple or lowest common denominator (LCD) can be calculated in three ways;
Least common multiple can be found by multiplying the highest exponent prime factors of 123 and 128. First we will calculate the prime factors of 123 and 128.
Prime Factorization of 123
3 | 123 |
41 | 41 |
1 |
Prime factors of 123 are 3,41. Prime factorization of 123 in exponential form is:
123 = 31×411
Prime Factorization of 128
2 | 128 |
2 | 64 |
2 | 32 |
2 | 16 |
2 | 8 |
2 | 4 |
2 | 2 |
1 |
Prime factors of 128 are 2. Prime factorization of 128 in exponential form is:
128 = 27
Now multiplying the highest exponent prime factors to calculate the LCM of 123 and 128.
LCM(123,128) = 27×31×411
LCM(123,128) = 15744
Factors of 123
List of positive integer factors of 123 that divides 123 without a remainder.
1, 3, 41, 123
Factors of 128
List of positive integer factors of 128 that divides 128 without a remainder.
1, 2, 4, 8, 16, 32, 64, 128
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 123 and 128, than apply into the LCM equation.
GCF(123,128) = 1
LCM(123,128) = ( 123 × 128) / 1
LCM(123,128) = 15744 / 1
LCM(123,128) = 15744
(i) The LCM of 128 and 123 is associative
LCM of 123 and 128 = LCM of 128 and 123
1. What is the LCM of 123 and 128?
Answer: LCM of 123 and 128 is 15744.
2. What are the Factors of 123?
Answer: Factors of 123 are 1, 3, 41, 123. There are 4 integers that are factors of 123. The greatest factor of 123 is 123.
3. What are the Factors of 128?
Answer: Factors of 128 are 1, 2, 4, 8, 16, 32, 64, 128. There are 8 integers that are factors of 128. The greatest factor of 128 is 128.
4. How to Find the LCM of 123 and 128?
Answer:
Least Common Multiple of 123 and 128 = 15744
Step 1: Find the prime factorization of 123
123 = 3 x 41
Step 2: Find the prime factorization of 128
128 = 2 x 2 x 2 x 2 x 2 x 2 x 2
Step 3: Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:
LCM = 15744 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 3 x 41
Step 4: Therefore, the least common multiple of 123 and 128 is 15744.