21,409 in words
21,409
twenty-one thousand four hundred and nine
21,409 is written twenty-one thousand four hundred and nine.
Ways to write it
- As an ordinal
- twenty-one thousand four hundred and ninth
- Expanded form
- 20,000 + 1,000 + 400 + 9
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 4 | 400 |
| tens | 0 | 0 |
| ones | 9 | 9 |
Number facts
- Even or odd
- Odd
- Prime or composite
- Composite
- Factors
- 1, 79, 271 and 21,409 (4 factors)
- First 10 multiples
- 21,409, 42,818, 64,227, 85,636, 107,045, 128,454, 149,863, 171,272, 192,681, 214,090
- Square
- 21,409 × 21,409 = 458,345,281
- Square root
- ≈ 146.32
- Sum of the digits
- 2 + 1 + 4 + 0 + 9 = 16
- Rounded to the nearest 10
- 21,410
- Rounded to the nearest 100
- 21,400
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,408
- Number after
- 21,410
- In binary
101001110100001
Quick check
What number comes just after 21,409?
Show the answer
21,410
Is 21,409 even or odd?
Show the answer
Odd
What is 21,409 + 10?
Show the answer
21,419
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 21,409 in words?
21,409 is written "twenty-one thousand four hundred and nine".
Is 21,409 a prime number?
No. 21,409 is a composite number, because it has more than two factors.
What are the factors of 21,409?
The factors of 21,409 are 1, 79, 271 and 21,409.