21,745 in words
21,745
twenty-one thousand seven hundred forty-five
21,745 is written twenty-one thousand seven hundred forty-five.
Ways to write it
- As an ordinal
- twenty-one thousand seven hundred forty-fifth
- Expanded form
- 20,000 + 1,000 + 700 + 40 + 5
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 7 | 700 |
| tens | 4 | 40 |
| ones | 5 | 5 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Composite
- Factors
- 1, 5, 4,349 and 21,745 (4 factors)
- First 10 multiples
- 21,745, 43,490, 65,235, 86,980, 108,725, 130,470, 152,215, 173,960, 195,705, 217,450
- Square
- 21,745 × 21,745 = 472,845,025
- Square root
- ≈ 147.46
- Sum of the digits
- 2 + 1 + 7 + 4 + 5 = 19
- Rounded to the nearest 10
- 21,750
- Rounded to the nearest 100
- 21,700
- Rounded to the nearest 1000
- 22,000
- Number before
- 21,744
- Number after
- 21,746
- In binary
101010011110001
Quick check
What number comes just after 21,745?
Show the answer
21,746
Is 21,745 even or odd?
Show the answer
Odd
What is 21,745 + 10?
Show the answer
21,755
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 21,745 in words?
21,745 is written "twenty-one thousand seven hundred forty-five".
Is 21,745 a prime number?
No. 21,745 is a composite number, because it has more than two factors.
What are the factors of 21,745?
The factors of 21,745 are 1, 5, 4,349 and 21,745.