LCM for 42 and 84

"Least Common Multiple" Calculator
Least Common Multiple of
and

What's the Least Common Multiple (LCM) of 42 and 84?

Answer

LCM of 42 and 84 is
84

(Eighty-four)

Finding LCM for 42 and 84 using GCF of these numbers

The first method to find LCM for numbers 42 and 84 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 42 and 84 is 42, so

LCM = (42 × 84) ÷ 42

LCM = 3,528 ÷ 42

LCM = 84

Finding LCM for 42 and 84 by Listing Multiples

The second method to find LCM for numbers 42 and 84 is to list out the common multiples for both numbers and pick the first one that matches:

Multiples of 42: 42, 84, 126, 168

Multiples of 84: 84, 168, 252

So the LCM for 42 and 84 is 84

Finding LCM for 42 and 84 by Prime Factorization

Another method to find LCM for numbers 42 and 84 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 42: 2, 3, 7 (exponent form: 21, 31, 71)

All Prime Factors of 84: 2, 2, 3, 7 (exponent form: 22, 31, 71)

22 × 31 × 71 = 84

Related Calculations

See Also

About "Least Common Multiple" Calculator

This calculator will help you find the Least Common Multiple (LCM) of two numbers. For example, it can help you find out what's the Least Common Multiple (LCM) of 42 and 84? (The answer is: 84). Select the first number (e.g. '42') and the second number (e.g. '84'). After that hit the 'Calculate' button.
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
"Least Common Multiple" Calculator
Least Common Multiple of
and

LCM Table

Number 1Number 2LCM
422884
4244924
4245630
4248336
4249294
42501,050
42521,092
42532,226
4256168
42581,218
4260420
42652,730
4270210
4272504
42801,680
428484
42861,806
4290630
4296672
4298294
421002,100
42105210
42126126
42231462
421,3652,730

FAQ

What's the Least Common Multiple (LCM) of 42 and 84?

LCM of 42 and 84 is 84

How to find the LCM of 42 and 84 using prime factorization?

To find the LCM of 42 and 84, find all prime factors of both numbers, then multiply the highest power of each prime factor. The result is 84.

What is the difference between LCM and GCF?

LCM (Least Common Multiple) is the smallest number divisible by both numbers, while GCF (Greatest Common Factor) is the largest number that divides both. For 42 and 84: LCM = 84, GCF = 42.

See Also