20,821 in words
20,821
twenty thousand eight hundred and twenty-one
20,821 is written twenty thousand eight hundred and twenty-one.
Ways to write it
- As an ordinal
- twenty thousand eight hundred and twenty-first
- Expanded form
- 20,000 + 800 + 20 + 1
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 0 | 0 |
| hundreds | 8 | 800 |
| tens | 2 | 20 |
| ones | 1 | 1 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Composite
- Factors
- 1, 47, 443 and 20,821 (4 factors)
- First 10 multiples
- 20,821, 41,642, 62,463, 83,284, 104,105, 124,926, 145,747, 166,568, 187,389, 208,210
- Square
- 20,821 × 20,821 = 433,514,041
- Square root
- ≈ 144.29
- Sum of the digits
- 2 + 0 + 8 + 2 + 1 = 13
- Rounded to the nearest 10
- 20,820
- Rounded to the nearest 100
- 20,800
- Rounded to the nearest 1000
- 21,000
- Number before
- 20,820
- Number after
- 20,822
- In binary
101000101010101
Quick check
What number comes just after 20,821?
Show the answer
20,822
Is 20,821 even or odd?
Show the answer
Odd
What is 20,821 + 10?
Show the answer
20,831
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 20,821 in words?
20,821 is written "twenty thousand eight hundred and twenty-one".
Is 20,821 a prime number?
No. 20,821 is a composite number, because it has more than two factors.
What are the factors of 20,821?
The factors of 20,821 are 1, 47, 443 and 20,821.