21,801 in words
21,801
twenty-one thousand eight hundred and one
21,801 is written twenty-one thousand eight hundred and one.
Ways to write it
- As an ordinal
- twenty-one thousand eight hundred and first
- Expanded form
- 20,000 + 1,000 + 800 + 1
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 8 | 800 |
| tens | 0 | 0 |
| ones | 1 | 1 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Composite
- Factors
- 1, 3, 13, 39, 43, 129, 169, 507, 559, 1,677, 7,267 and 21,801 (12 factors)
- First 10 multiples
- 21,801, 43,602, 65,403, 87,204, 109,005, 130,806, 152,607, 174,408, 196,209, 218,010
- Square
- 21,801 × 21,801 = 475,283,601
- Square root
- ≈ 147.65
- Sum of the digits
- 2 + 1 + 8 + 0 + 1 = 12
- Rounded to the nearest 10
- 21,800
- Rounded to the nearest 100
- 21,800
- Rounded to the nearest 1000
- 22,000
- Number before
- 21,800
- Number after
- 21,802
- In binary
101010100101001
Quick check
What number comes just after 21,801?
Show the answer
21,802
Is 21,801 even or odd?
Show the answer
Odd
What is 21,801 + 10?
Show the answer
21,811
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 21,801 in words?
21,801 is written "twenty-one thousand eight hundred and one".
Is 21,801 a prime number?
No. 21,801 is a composite number, because it has more than two factors.
What are the factors of 21,801?
The factors of 21,801 are 1, 3, 13, 39, 43, 129, 169, 507, 559, 1,677, 7,267 and 21,801.