LCM for 2, 5 and 8

"Least Common Multiple of 3 Numbers" Calculator
Least Common Multiple of
,
and

What's the Least Common Multiple (LCM) of 2, 5 and 8?

Answer

LCM of 2, 5 and 8 is
40

(Forty)

40 is the smallest positive integer that 2, 5 and 8 all divide without a remainder — every other common multiple of the three is a multiple of it.

Finding the LCM of 2, 5 and 8 by Prime Factorization

Split all three numbers into prime factors, then take every prime that shows up in at least one of them, each raised to the highest power it reaches there. Multiplying those highest powers gives the least common multiple:

All Prime Factors of 2: 2 (exponent form: 2)

All Prime Factors of 5: 5 (exponent form: 5)

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

Prime factor258Highest power
22—2323
5—5—5

LCM = 23 × 5 = 40

Checking the LCM of 2, 5 and 8 Two Numbers at a Time

The least common multiple is associative, so three numbers can be handled as two pairs: first the LCM of the first two, then the LCM of that value and the third. Each pair goes through the two-number formula, which uses the greatest common divisor:

LCM(a, b) = (a × b) ÷ GCD(a, b)

LCM(2, 5) = (2 × 5) ÷ 1 = 10 ÷ 1 = 10

LCM(10, 8) = (10 × 8) ÷ 2 = 80 ÷ 2 = 40

LCM(2, 5, 8) = 40

The pairs may be taken in any order — 5 and 8 first, then 2 — and the answer is the same 40. That is exactly why the two routes on this page agree.

Related Calculations

See Also

About "Least Common Multiple of 3 Numbers" Calculator

This calculator finds the Least Common Multiple (LCM) of three numbers at once, without doing it in two passes. For example, it can help you find out what's the Least Common Multiple (LCM) of 2, 5 and 8? (The answer is: 40). Enter the first number (e.g. '2'), the second (e.g. '5') and the third (e.g. '8'), then hit the 'Calculate' button.
The Least Common Multiple of three numbers is the smallest positive integer that all three of them divide without a remainder
"Least Common Multiple of 3 Numbers" Calculator
Least Common Multiple of
,
and

LCM Table

Number 1Number 2Number 3LCM
12510
22510
23530
24520
25510
25630
25770
25840
25990
251010
2511110
251260
2513130
251470
251530
251680
2517170
251890
2519190
252020
2521210
2522110
2523230
2524120
252550
2526130
2527270
2528140
2529290
253030

FAQ

What's the Least Common Multiple (LCM) of 2, 5 and 8?

LCM of 2, 5 and 8 is 40

How to find the LCM of 2, 5 and 8 by prime factorization?

Take every prime that appears in 2, 5 and 8 to the highest power it reaches in any one of them and multiply: 2³ × 5 = 40.

Can you get the LCM of 2, 5 and 8 two numbers at a time?

Yes, and it is the check this page prints. The LCM of 2 and 5 is 10, and the LCM of 10 and 8 is 40 — the same answer, because the least common multiple is associative and does not depend on the order of the three numbers.

Is 40 divisible by 2, 5 and 8?

Yes, and by definition it is the smallest positive integer that is: 40 ÷ 2, 40 ÷ 5 and 40 ÷ 8 all come out whole. Any other common multiple of 2, 5 and 8 is a multiple of 40.

See Also