LCM for 28 and 42

"Least Common Multiple" Calculator

Least Common Multiple of

and

What's the Least Common Multiple (LCM) of 28 and 42?

Answer

LCM of 28 and 42 is 84

(Eighty-four)

Finding LCM for 28 and 42 using GCF of these numbers

The first method to find LCM for numbers 28 and 42 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 28 and 42 is 14, so

LCM = (28 × 42) ÷ 14

LCM = 1176 ÷ 14

LCM = 84

Finding LCM for 28 and 42 by Listing Multiples

The second method to find LCM for numbers 28 and 42 is to list out the common multiples for both numbers and pick the first one that matches:

Multiples of 28: 28, 56, 84, 112, 140

Multiples of 42: 42, 84, 126, 168

So the LCM for 28 and 42 is 84

Finding LCM for 28 and 42 by Prime Factorization

Another method to find LCM for numbers 28 and 42 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 28: 2, 2, 7 (exponent form: 22, 71)

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

22 × 71 × 31 = 84

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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 28 and 42? (The answer is: 84). Select the first number (e.g. '28') and the second number (e.g. '42'). 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

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LCM Table

Number 1 Number 2 LCM
13 42 546
14 42 42
15 42 210
16 42 336
17 42 714
18 42 126
19 42 798
20 42 420
21 42 42
22 42 462
23 42 966
24 42 168
25 42 1050
26 42 546
27 42 378
28 42 84
29 42 1218
30 42 210
31 42 1302
32 42 672
33 42 462
34 42 714
35 42 210
36 42 252
37 42 1554
38 42 798
39 42 546
40 42 840
41 42 1722
42 42 42

FAQ

What's the Least Common Multiple (LCM) of 28 and 42?
LCM of 28 and 42 is 84

How to find the LCM of 28 and 42 using prime factorization?
To find the LCM of 28 and 42, 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 28 and 42: LCM = 84, GCF = 14.

See Also