21,109 in words
21,109
twenty-one thousand one hundred nine
21,109 is written twenty-one thousand one hundred nine.
Ways to write it
- As an ordinal
- twenty-one thousand one hundred ninth
- Expanded form
- 20,000 + 1,000 + 100 + 9
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 1 | 100 |
| tens | 0 | 0 |
| ones | 9 | 9 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Composite
- Factors
- 1, 11, 19, 101, 209, 1,111, 1,919 and 21,109 (8 factors)
- First 10 multiples
- 21,109, 42,218, 63,327, 84,436, 105,545, 126,654, 147,763, 168,872, 189,981, 211,090
- Square
- 21,109 × 21,109 = 445,589,881
- Square root
- ≈ 145.29
- Sum of the digits
- 2 + 1 + 1 + 0 + 9 = 13
- Rounded to the nearest 10
- 21,110
- Rounded to the nearest 100
- 21,100
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,108
- Number after
- 21,110
- In binary
101001001110101
Quick check
What number comes just after 21,109?
Show the answer
21,110
Is 21,109 even or odd?
Show the answer
Odd
What is 21,109 + 10?
Show the answer
21,119
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 21,109 in words?
21,109 is written "twenty-one thousand one hundred nine".
Is 21,109 a prime number?
No. 21,109 is a composite number, because it has more than two factors.
What are the factors of 21,109?
The factors of 21,109 are 1, 11, 19, 101, 209, 1,111, 1,919 and 21,109.