LCM for 21 and 43

"Least Common Multiple" Calculator

Least Common Multiple of

and

What's the Least Common Multiple (LCM) of 21 and 43?

Answer

LCM of 21 and 43 is 903

(Nine hundred three)

Finding LCM for 21 and 43 using GCF of these numbers

The first method to find LCM for numbers 21 and 43 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 21 and 43 is 1, so

LCM = (21 × 43) ÷ 1

LCM = 903 ÷ 1

LCM = 903

Finding LCM for 21 and 43 by Listing Multiples

The second method to find LCM for numbers 21 and 43 is to list out the common multiples for both numbers and pick the first one that matches:

Multiples of 21: 21, 42, 63, 84, 105, 126, 147, 168, 189, 210, 231, 252, 273, 294, 315, 336, 357, 378, 399, 420, 441, 462, 483, 504, 525, 546, 567, 588, 609, 630, 651, 672, 693, 714, 735, 756, 777, 798, 819, 840, 861, 882, 903, 924, 945

Multiples of 43: 43, 86, 129, 172, 215, 258, 301, 344, 387, 430, 473, 516, 559, 602, 645, 688, 731, 774, 817, 860, 903, 946, 989

So the LCM for 21 and 43 is 903

Finding LCM for 21 and 43 by Prime Factorization

Another method to find LCM for numbers 21 and 43 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

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

All Prime Factors of 43: 43 (exponent form: 431)

31 × 71 × 431 = 903

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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 21 and 43? (The answer is: 903). Select the first number (e.g. '21') and the second number (e.g. '43'). 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
643258
743301
843344
943387
1043430
1143473
1243516
1343559
1443602
1543645
1643688
1743731
1843774
1943817
2043860
2143903
2243946
2343989
24431032
25431075
26431118
27431161
28431204
29431247
30431290
31431333
32431376
33431419
34431462
35431505

FAQ

What's the Least Common Multiple (LCM) of 21 and 43?

LCM of 21 and 43 is 903

How to find the LCM of 21 and 43 using prime factorization?

To find the LCM of 21 and 43, find all prime factors of both numbers, then multiply the highest power of each prime factor. The result is 903.

What is the difference between LCM and GCF?

LCM (Least Common Multiple) is the smallest number divisible by both numbers, while GCF (Greatest Common Factor) is the largest number that divides both. For 21 and 43: LCM = 903, GCF = 1.

See Also