21,311 in words
21,311
twenty-one thousand three hundred eleven
21,311 is written twenty-one thousand three hundred eleven.
Ways to write it
- As an ordinal
- twenty-one thousand three hundred eleventh
- Expanded form
- 20,000 + 1,000 + 300 + 10 + 1
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 3 | 300 |
| tens | 1 | 10 |
| ones | 1 | 1 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Composite
- Factors
- 1, 101, 211 and 21,311 (4 factors)
- First 10 multiples
- 21,311, 42,622, 63,933, 85,244, 106,555, 127,866, 149,177, 170,488, 191,799, 213,110
- Square
- 21,311 × 21,311 = 454,158,721
- Square root
- ≈ 145.98
- Sum of the digits
- 2 + 1 + 3 + 1 + 1 = 8
- Rounded to the nearest 10
- 21,310
- Rounded to the nearest 100
- 21,300
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,310
- Number after
- 21,312
- In binary
101001100111111
Quick check
What number comes just after 21,311?
Show the answer
21,312
Is 21,311 even or odd?
Show the answer
Odd
What is 21,311 + 10?
Show the answer
21,321
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 21,311 in words?
21,311 is written "twenty-one thousand three hundred eleven".
Is 21,311 a prime number?
No. 21,311 is a composite number, because it has more than two factors.
What are the factors of 21,311?
The factors of 21,311 are 1, 101, 211 and 21,311.