Least Common Multiple of 4, 7, and 21 (LCM of 4, 7, and 21)

Least Common Multiple (LCM) of 4, 7, and 21

What is the Least Common Multiple (LCM) of 4, 7, and 21? Here we will show you step-by-step how to find the Least Common Multiple of 4, 7, and 21.

Step 1) First we find and list the prime factors of 4, 7, and 21 (Prime Factorization):

Prime Factors of 4:
2, 2

Prime Factors of 7:
7

Prime Factors of 21:
3, 7

Step 2) Then we look at the frequency of the prime factors as they appear in each set above. List each prime factor the greatest number of times it occurs in any of the sets:

2, 2, 3, 7

Step 3) Finally, we multiply the prime numbers from Step 2 together.

2 x 2 x 3 x 7 = 84

That's it. The Least Common Multiple (LCM) of 4, 7, and 21 is 84.

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Least Common Multiple (LCM) of 4, 7, and 22
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