LCM for 6 and 21
What's the Least Common Multiple (LCM) of 6 and 21?
(Forty-two)
Finding LCM for 6 and 21 using GCF's of these numbers
The first method to find LCM for numbers 6 and 21 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 6 and 21 is 3, so
LCM = (6 × 21) ÷ 3
LCM = 126 ÷ 3
LCM = 42
Finding LCM for 6 and 21 by Listing Multiples
The second method to find LCM for numbers 6 and 21 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54
Multiples of 21: 21, 42, 63, 84
So the LCM for 6 and 21 is 42
Finding LCM for 6 and 21 by Prime Factorization
Another method to find LCM for numbers 6 and 21 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 6: 2, 3 (exponent form: 21, 31)
All Prime Factors of 21: 3, 7 (exponent form: 31, 71)
21 × 31 × 71 = 42
Related Calculations
See Also
- Greatest Common Factor - Find the Greatest Common Factor (GCF) of two numbers
<a href="https://calculat.io/en/number/least-common-multiple-lcm-of/6--21">What is the LCM of 6 and 21? - Calculatio</a>
LCM Table
About "Least Common Multiple" Calculator
Least Common Multiple (LCM) also known as the Lowest Common Multiple or Smallest Common Multiple of 2 numbers - it is the smallest positive integer that is divisible by both numbers