21,428 in words
21,428
twenty-one thousand four hundred twenty-eight
21,428 is written twenty-one thousand four hundred twenty-eight.
Ways to write it
- As an ordinal
- twenty-one thousand four hundred twenty-eighth
- Expanded form
- 20,000 + 1,000 + 400 + 20 + 8
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 4 | 400 |
| tens | 2 | 20 |
| ones | 8 | 8 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 4, 11, 22, 44, 487, 974, 1,948, 5,357, 10,714 and 21,428 (12 factors)
- First 10 multiples
- 21,428, 42,856, 64,284, 85,712, 107,140, 128,568, 149,996, 171,424, 192,852, 214,280
- Square
- 21,428 × 21,428 = 459,159,184
- Square root
- ≈ 146.38
- Sum of the digits
- 2 + 1 + 4 + 2 + 8 = 17
- Rounded to the nearest 10
- 21,430
- Rounded to the nearest 100
- 21,400
- Rounded to the nearest 1000
- 21,000
- Number before
- 21,427
- Number after
- 21,429
- In binary
101001110110100
Quick check
What number comes just after 21,428?
Show the answer
21,429
Is 21,428 even or odd?
Show the answer
Even
What is 21,428 + 10?
Show the answer
21,438
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 21,428 in words?
21,428 is written "twenty-one thousand four hundred twenty-eight".
Is 21,428 a prime number?
No. 21,428 is a composite number, because it has more than two factors.
What are the factors of 21,428?
The factors of 21,428 are 1, 2, 4, 11, 22, 44, 487, 974, 1,948, 5,357, 10,714 and 21,428.