21,040 in words
21,040
twenty-one thousand forty
21,040 is written twenty-one thousand forty.
Ways to write it
- As an ordinal
- twenty-one thousand fortieth
- Expanded form
- 20,000 + 1,000 + 40
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 0 | 0 |
| tens | 4 | 40 |
| ones | 0 | 0 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 263, 526, 1,052, 1,315, 2,104, 2,630, 4,208, 5,260, 10,520 and 21,040 (20 factors)
- First 10 multiples
- 21,040, 42,080, 63,120, 84,160, 105,200, 126,240, 147,280, 168,320, 189,360, 210,400
- Square
- 21,040 × 21,040 = 442,681,600
- Square root
- ≈ 145.05
- Sum of the digits
- 2 + 1 + 0 + 4 + 0 = 7
- Rounded to the nearest 10
- 21,040
- Rounded to the nearest 100
- 21,000
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,039
- Number after
- 21,041
- In binary
101001000110000
Quick check
What number comes just after 21,040?
Show the answer
21,041
Is 21,040 even or odd?
Show the answer
Even
What is 21,040 + 10?
Show the answer
21,050
Practice 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 21,040 in words?
21,040 is written "twenty-one thousand forty".
Is 21,040 a prime number?
No. 21,040 is a composite number, because it has more than two factors.
What are the factors of 21,040?
The factors of 21,040 are 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 263, 526, 1,052, 1,315, 2,104, 2,630, 4,208, 5,260, 10,520 and 21,040.