LCM for 21 and 39
What's the Least Common Multiple (LCM) of 21 and 39?
(Two hundred seventy-three)
Finding LCM for 21 and 39 using GCF's of these numbers
The first method to find LCM for numbers 21 and 39 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 21 and 39 is 3, so
LCM = (21 × 39) ÷ 3
LCM = 819 ÷ 3
LCM = 273
Finding LCM for 21 and 39 by Listing Multiples
The second method to find LCM for numbers 21 and 39 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, 210, 231, 252, 273, 294, 315
Multiples of 39: 39, 78, 117, 156, 195, 234, 273, 312, 351
So the LCM for 21 and 39 is 273
Finding LCM for 21 and 39 by Prime Factorization
Another method to find LCM for numbers 21 and 39 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 39: 3, 13 (exponent form: 31, 131)
31 × 71 × 131 = 273
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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