LCM for 5, 14 and 20

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

What's the Least Common Multiple (LCM) of 5, 14 and 20?

Answer

LCM of 5, 14 and 20 is
140

(One hundred forty)

140 is the smallest positive integer that 5, 14 and 20 all divide without a remainder — every other common multiple of the three is a multiple of it.

Finding the LCM of 5, 14 and 20 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 5: 5 (exponent form: 5)

All Prime Factors of 14: 2 × 7 (exponent form: 2 × 7)

All Prime Factors of 20: 2 × 2 × 5 (exponent form: 22 × 5)

Prime factor51420Highest power
2—22222
55—55
7—7—7

LCM = 22 × 5 × 7 = 140

Checking the LCM of 5, 14 and 20 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(5, 14) = (5 × 14) ÷ 1 = 70 ÷ 1 = 70

LCM(70, 20) = (70 × 20) ÷ 10 = 1,400 ÷ 10 = 140

LCM(5, 14, 20) = 140

The pairs may be taken in any order — 14 and 20 first, then 5 — and the answer is the same 140. 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 5, 14 and 20? (The answer is: 140). Enter the first number (e.g. '5'), the second (e.g. '14') and the third (e.g. '20'), 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
551470
5614210
571470
5814280
5914630
5101470
51114770
51214420
51314910
5141470
51415210
51416560
514171,190
51418630
514191,330
51420140
51421210
51422770
514231,610
51424840
51425350
51426910
514271,890
51428140
514292,030
51430210
514312,170
514321,120
514332,310
514341,190

FAQ

What's the Least Common Multiple (LCM) of 5, 14 and 20?

LCM of 5, 14 and 20 is 140

How to find the LCM of 5, 14 and 20 by prime factorization?

Take every prime that appears in 5, 14 and 20 to the highest power it reaches in any one of them and multiply: 2² × 5 × 7 = 140.

Can you get the LCM of 5, 14 and 20 two numbers at a time?

Yes, and it is the check this page prints. The LCM of 5 and 14 is 70, and the LCM of 70 and 20 is 140 — the same answer, because the least common multiple is associative and does not depend on the order of the three numbers.

Is 140 divisible by 5, 14 and 20?

Yes, and by definition it is the smallest positive integer that is: 140 ÷ 5, 140 ÷ 14 and 140 ÷ 20 all come out whole. Any other common multiple of 5, 14 and 20 is a multiple of 140.

See Also