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
2115105
2122462
2123483
2124168
2125525
2126546
212884
2129609
2130210
2132672
2134714
2135105
2136252
2139273
2141861
214242
2143903
2144924
2145315
2147987
2148336
2149147
2151357
21521092
21531113
21551155
2156168
21581218
21591239
2160420

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