LCM for 21 and 49
What's the Least Common Multiple (LCM) of 21 and 49?
(One hundred forty-seven)
Finding LCM for 21 and 49 using GCF's of these numbers
The first method to find LCM for numbers 21 and 49 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 21 and 49 is 7, so
LCM = (21 × 49) ÷ 7
LCM = 1029 ÷ 7
LCM = 147
Finding LCM for 21 and 49 by Listing Multiples
The second method to find LCM for numbers 21 and 49 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 21: 21, 42, 63, 84, 105, 126, 147, 168, 189
Multiples of 49: 49, 98, 147, 196, 245
So the LCM for 21 and 49 is 147
Finding LCM for 21 and 49 by Prime Factorization
Another method to find LCM for numbers 21 and 49 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 21: 3, 7 (exponent form: 31, 71)
All Prime Factors of 49: 7, 7 (exponent form: 72)
31 × 72 = 147
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/21--49">What is the LCM of 21 and 49? - 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