LCM for 18 and 81
What's the Least Common Multiple (LCM) of 18 and 81?
(One hundred sixty-two)
Finding LCM for 18 and 81 using GCF's of these numbers
The first method to find LCM for numbers 18 and 81 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 18 and 81 is 9, so
LCM = (18 × 81) ÷ 9
LCM = 1458 ÷ 9
LCM = 162
Finding LCM for 18 and 81 by Listing Multiples
The second method to find LCM for numbers 18 and 81 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 18: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, 198
Multiples of 81: 81, 162, 243, 324
So the LCM for 18 and 81 is 162
Finding LCM for 18 and 81 by Prime Factorization
Another method to find LCM for numbers 18 and 81 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 18: 2, 3, 3 (exponent form: 21, 32)
All Prime Factors of 81: 3, 3, 3, 3 (exponent form: 34)
21 × 34 = 162
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/18--81">What is the LCM of 18 and 81? - 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