Least Common Multiple (LCM) of 21 and 128
The least common multiple (LCM) of 21 and 128 is 2688.
What is the Least Common Multiple (LCM)?
The LCM of two integers is the smallest positive integer that is divisible by both numbers. It is often used to find common denominators and solve problems involving periodic events.
Formula for LCM
The LCM of two numbers can be calculated using their GCD:
LCM(a, b) = |a × b| ÷ GCD(a, b)
How to Calculate the LCM of 21 and 128?
First, calculate the GCD of 21 and 128 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 128 = 0 remainder 21 |
| 2 | 128 ÷ 21 = 6 remainder 2 |
| 3 | 21 ÷ 2 = 10 remainder 1 |
| 4 | 2 ÷ 1 = 2 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 193 and 115 | 22195 |
| 103 and 154 | 15862 |
| 44 and 71 | 3124 |
| 80 and 79 | 6320 |
| 94 and 95 | 8930 |