LCM for 3 and 7

"Least Common Multiple" Calculator

Least Common Multiple of

and

What's the Least Common Multiple (LCM) of 3 and 7?

Answer: LCM of 3 and 7 is 21

(Twenty-one)

Finding LCM for 3 and 7 using GCF's of these numbers

The first method to find LCM for numbers 3 and 7 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 3 and 7 is 1, so

LCM = (3 × 7) ÷ 1

LCM = 21 ÷ 1

LCM = 21

Finding LCM for 3 and 7 by Listing Multiples

The second method to find LCM for numbers 3 and 7 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27

Multiples of 7: 7, 14, 21, 28, 35

So the LCM for 3 and 7 is 21

Finding LCM for 3 and 7 by Prime Factorization

Another method to find LCM for numbers 3 and 7 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 3: 3 (exponent form: 31)

All Prime Factors of 7: 7 (exponent form: 71)

31 × 71 = 21

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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 3 and 7? (The answer is: 21). Select the first number (e.g. '3') and the second number (e.g. '7'). 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
177
2714
3721
4728
5735
6742
777
8756
9763
10770
11777
12784
13791
14714
157105
167112
177119
187126
197133
207140
21721
227154
237161
247168
257175
267182
277189
28728
297203
307210

FAQ

What's the Least Common Multiple (LCM) of 3 and 7?

LCM of 3 and 7 is 21

See Also