21,240 in words
21,240
twenty-one thousand two hundred forty
21,240 is written twenty-one thousand two hundred forty.
Ways to write it
- As an ordinal
- twenty-one thousand two hundred fortieth
- Expanded form
- 20,000 + 1,000 + 200 + 40
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 2 | 200 |
| tens | 4 | 40 |
| ones | 0 | 0 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 59, 60, 72, 90, 118, 120, 177, 180, 236, 295, 354, 360, 472, 531, 590, 708, 885, 1,062, 1,180, 1,416, 1,770, 2,124, 2,360, 2,655, 3,540, 4,248, 5,310, 7,080, 10,620 and 21,240 (48 factors)
- First 10 multiples
- 21,240, 42,480, 63,720, 84,960, 106,200, 127,440, 148,680, 169,920, 191,160, 212,400
- Square
- 21,240 × 21,240 = 451,137,600
- Square root
- ≈ 145.74
- Sum of the digits
- 2 + 1 + 2 + 4 + 0 = 9
- Rounded to the nearest 10
- 21,240
- Rounded to the nearest 100
- 21,200
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,239
- Number after
- 21,241
- In binary
101001011111000
Quick check
What number comes just after 21,240?
Show the answer
21,241
Is 21,240 even or odd?
Show the answer
Even
What is 21,240 + 10?
Show the answer
21,250
Practise with a game
Factors, Multiples & Primes
Multiples, factors, prime numbers, square numbers and prime factors.
Number Patterns
Find the missing number in a sequence.Frequently asked questions
How do you write 21,240 in words?
21,240 is written "twenty-one thousand two hundred forty".
Is 21,240 a prime number?
No. 21,240 is a composite number, because it has more than two factors.
What are the factors of 21,240?
The factors of 21,240 are 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 59, 60, 72, 90, 118, 120, 177, 180, 236, 295, 354, 360, 472, 531, 590, 708, 885, 1,062, 1,180, 1,416, 1,770, 2,124, 2,360, 2,655, 3,540, 4,248, 5,310, 7,080, 10,620 and 21,240.