21,397 in words
21,397
twenty-one thousand three hundred ninety-seven
21,397 is written twenty-one thousand three hundred ninety-seven.
Ways to write it
- As an ordinal
- twenty-one thousand three hundred ninety-seventh
- Expanded form
- 20,000 + 1,000 + 300 + 90 + 7
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 3 | 300 |
| tens | 9 | 90 |
| ones | 7 | 7 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Prime
- Factors
- 1 and 21,397 (2 factors)
- First 10 multiples
- 21,397, 42,794, 64,191, 85,588, 106,985, 128,382, 149,779, 171,176, 192,573, 213,970
- Square
- 21,397 × 21,397 = 457,831,609
- Square root
- ≈ 146.28
- Sum of the digits
- 2 + 1 + 3 + 9 + 7 = 22
- Rounded to the nearest 10
- 21,400
- Rounded to the nearest 100
- 21,400
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,396
- Number after
- 21,398
- In binary
101001110010101
Quick check
What number comes just after 21,397?
Show the answer
21,398
Is 21,397 even or odd?
Show the answer
Odd
What is 21,397 + 10?
Show the answer
21,407
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 21,397 in words?
21,397 is written "twenty-one thousand three hundred ninety-seven".
Is 21,397 a prime number?
Yes. 21,397 is a prime number: its only factors are 1 and 21,397.
What are the factors of 21,397?
The factors of 21,397 are 1 and 21,397.