21,042 in words
21,042
twenty-one thousand and forty-two
21,042 is written twenty-one thousand and forty-two.
Ways to write it
- As an ordinal
- twenty-one thousand and forty-second
- Expanded form
- 20,000 + 1,000 + 40 + 2
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 0 | 0 |
| tens | 4 | 40 |
| ones | 2 | 2 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126, 167, 334, 501, 1,002, 1,169, 1,503, 2,338, 3,006, 3,507, 7,014, 10,521 and 21,042 (24 factors)
- First 10 multiples
- 21,042, 42,084, 63,126, 84,168, 105,210, 126,252, 147,294, 168,336, 189,378, 210,420
- Square
- 21,042 × 21,042 = 442,765,764
- Square root
- ≈ 145.06
- Sum of the digits
- 2 + 1 + 0 + 4 + 2 = 9
- Rounded to the nearest 10
- 21,040
- Rounded to the nearest 100
- 21,000
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,041
- Number after
- 21,043
- In binary
101001000110010
Quick check
What number comes just after 21,042?
Show the answer
21,043
Is 21,042 even or odd?
Show the answer
Even
What is 21,042 + 10?
Show the answer
21,052
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 21,042 in words?
21,042 is written "twenty-one thousand and forty-two".
Is 21,042 a prime number?
No. 21,042 is a composite number, because it has more than two factors.
What are the factors of 21,042?
The factors of 21,042 are 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126, 167, 334, 501, 1,002, 1,169, 1,503, 2,338, 3,006, 3,507, 7,014, 10,521 and 21,042.