Multiples of 21: First 20 Multiples

Multiples Calculator

Use the calculator above to find the first 20 multiples of any positive integer up to 10,000. A multiple of n is any number obtained by multiplying n by a natural number: n × 1, n × 2, n × 3, ... Beyond the multiples list, this tool shows the sum, average, full multiplication table, and links to the divisor pages of each multiple.

First Multiples of 21

First 5 Multiples of 21

The first 5 multiples of 21 are: 21, 42, 63, 84, 105.

First 10 Multiples of 21

The first 10 multiples of 21 are: 21, 42, 63, 84, 105, 126, 147, 168, 189, 210.

First 20 Multiples of 21

The first 20 multiples of 21 are: 21, 42, 63, 84, 105, 126, 147, 168, 189, 210, 231, 252, 273, 294, 315, 336, 357, 378, 399, 420.

Sum: 4410.  Average: 220.5.

Multiplication Table for 21

See Divisors of Each Multiple

Since each multiple of 21 has 21 as one of its divisors, here are the divisor pages for the first 8 multiples:

• Divisors of 21
• Divisors of 42
• Divisors of 63
• Divisors of 84
• Divisors of 105
• Divisors of 126
• Divisors of 147
• Divisors of 168

Step-by-Step: How to List the Multiples of 21

A multiple of n is the result of multiplying n by any natural number (1, 2, 3, ...). To list the first k multiples, just multiply 21 by each integer from 1 to k:

1. 21 × 1 = 21
2. 21 × 2 = 42
3. 21 × 3 = 63
4. …continue up to 21 × 20 = 420.
5. Sum of these 20 multiples: 21 × (1+2+…+20) = 21 × 210 = 4410.

Shortcut: the sum of the first 20 multiples of 21 always equals 210n, since 1+2+…+20 = 210.

Facts About Multiples

• Any number is a multiple of itself (n × 1 = n).
• Any number is a multiple of 1 (1 × n = n).
• Zero is a multiple of any number (0 × n = 0).
• The set of multiples of a number is infinite — every natural-number multiplier produces another multiple.
• If two numbers a and b are multiplied, the product a × b is a common multiple of both (but not necessarily the least common multiple — LCM).

The set of multiples of n can be represented as M_n = {0, 1·n, 2·n, 3·n, …}. For example: M₂₁ = {0, 21, 42, 63, 84, …}.

Nearby Examples

Multiples Table

• 1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
• 2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40
• 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60
• 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80
• 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100
• 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120
• 7: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140
• 8: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160
• 9: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135, 144, 153, 162, 171, 180
• 10: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200
• 11: 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 121, 132, 143, 154, 165, 176, 187, 198, 209, 220
• 12: 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240
• 13: 13, 26, 39, 52, 65, 78, 91, 104, 117, 130, 143, 156, 169, 182, 195, 208, 221, 234, 247, 260
• 14: 14, 28, 42, 56, 70, 84, 98, 112, 126, 140, 154, 168, 182, 196, 210, 224, 238, 252, 266, 280
• 15: 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 240, 255, 270, 285, 300

Related Operations for 21

• Divisors (factors) of 21 — "inward" complement (every divisor of N is also a divisor of its multiples)
• 21 Prime Factorization
• GCF of 21 and another number
• LCM of 21 and another number

References

• [1] Múltiplos e Divisores — atractor.pt
• [2] Multiple (mathematics) — Wikipedia

Multiples Examples

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