LCM for 8 and 21

What's the Least Common Multiple (LCM) of 8 and 21?

Answer: LCM of 8 and 21 is 168

(One hundred sixty-eight)

Finding LCM for 8 and 21 using GCF's of these numbers

The first method to find LCM for numbers 8 and 21 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 8 and 21 is 1, so

LCM = (8 × 21) ÷ 1

LCM = 168 ÷ 1

LCM = 168

Finding LCM for 8 and 21 by Listing Multiples

The second method to find LCM for numbers 8 and 21 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 8: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184

Multiples of 21: 21, 42, 63, 84, 105, 126, 147, 168, 189, 210

So the LCM for 8 and 21 is 168

Finding LCM for 8 and 21 by Prime Factorization

Another method to find LCM for numbers 8 and 21 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 8: 2, 2, 2 (exponent form: 23)

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

23 × 31 × 71 = 168

LCM Table

Number 1Number 2LCM
12121
22142
321
42184
521
621
721
821
921
1021
1121231
1221
1321
1421
1521
1621
1721357
1821
1921399
2021
212121
2221462
2321483
2421168
2521525
2621546
2721189
282184
2921609
3021210

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 8 and 21? (The answer is: 168). Select the first number (e.g. '8') and the second number (e.g. '21'). 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

FAQ

What's the Least Common Multiple (LCM) of 8 and 21?

LCM of 8 and 21 is 168