21,408 in words
21,408
twenty-one thousand four hundred eight
21,408 is written twenty-one thousand four hundred eight.
Ways to write it
- As an ordinal
- twenty-one thousand four hundred eighth
- Expanded form
- 20,000 + 1,000 + 400 + 8
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 4 | 400 |
| tens | 0 | 0 |
| ones | 8 | 8 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96, 223, 446, 669, 892, 1,338, 1,784, 2,676, 3,568, 5,352, 7,136, 10,704 and 21,408 (24 factors)
- First 10 multiples
- 21,408, 42,816, 64,224, 85,632, 107,040, 128,448, 149,856, 171,264, 192,672, 214,080
- Square
- 21,408 × 21,408 = 458,302,464
- Square root
- ≈ 146.31
- Sum of the digits
- 2 + 1 + 4 + 0 + 8 = 15
- Rounded to the nearest 10
- 21,410
- Rounded to the nearest 100
- 21,400
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,407
- Number after
- 21,409
- In binary
101001110100000
Quick check
What number comes just after 21,408?
Show the answer
21,409
Is 21,408 even or odd?
Show the answer
Even
What is 21,408 + 10?
Show the answer
21,418
Practice 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 21,408 in words?
21,408 is written "twenty-one thousand four hundred eight".
Is 21,408 a prime number?
No. 21,408 is a composite number, because it has more than two factors.
What are the factors of 21,408?
The factors of 21,408 are 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96, 223, 446, 669, 892, 1,338, 1,784, 2,676, 3,568, 5,352, 7,136, 10,704 and 21,408.