21,842 in words
21,842
twenty-one thousand eight hundred forty-two
21,842 is written twenty-one thousand eight hundred forty-two.
Ways to write it
- As an ordinal
- twenty-one thousand eight hundred forty-second
- Expanded form
- 20,000 + 1,000 + 800 + 40 + 2
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 8 | 800 |
| tens | 4 | 40 |
| ones | 2 | 2 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 67, 134, 163, 326, 10,921 and 21,842 (8 factors)
- First 10 multiples
- 21,842, 43,684, 65,526, 87,368, 109,210, 131,052, 152,894, 174,736, 196,578, 218,420
- Square
- 21,842 × 21,842 = 477,072,964
- Square root
- ≈ 147.79
- Sum of the digits
- 2 + 1 + 8 + 4 + 2 = 17
- Rounded to the nearest 10
- 21,840
- Rounded to the nearest 100
- 21,800
- Rounded to the nearest 1000
- 22,000
- Number before
- 21,841
- Number after
- 21,843
- In binary
101010101010010
Quick check
What number comes just after 21,842?
Show the answer
21,843
Is 21,842 even or odd?
Show the answer
Even
What is 21,842 + 10?
Show the answer
21,852
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 21,842 in words?
21,842 is written "twenty-one thousand eight hundred forty-two".
Is 21,842 a prime number?
No. 21,842 is a composite number, because it has more than two factors.
What are the factors of 21,842?
The factors of 21,842 are 1, 2, 67, 134, 163, 326, 10,921 and 21,842.