21,680 in words
21,680
twenty-one thousand six hundred and eighty
21,680 is written twenty-one thousand six hundred and eighty.
Ways to write it
- As an ordinal
- twenty-one thousand six hundred and eightieth
- Expanded form
- 20,000 + 1,000 + 600 + 80
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 6 | 600 |
| tens | 8 | 80 |
| ones | 0 | 0 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 271, 542, 1,084, 1,355, 2,168, 2,710, 4,336, 5,420, 10,840 and 21,680 (20 factors)
- First 10 multiples
- 21,680, 43,360, 65,040, 86,720, 108,400, 130,080, 151,760, 173,440, 195,120, 216,800
- Square
- 21,680 × 21,680 = 470,022,400
- Square root
- ≈ 147.24
- Sum of the digits
- 2 + 1 + 6 + 8 + 0 = 17
- Rounded to the nearest 10
- 21,680
- Rounded to the nearest 100
- 21,700
- Rounded to the nearest 1000
- 22,000
- Number before
- 21,679
- Number after
- 21,681
- In binary
101010010110000
Quick check
What number comes just after 21,680?
Show the answer
21,681
Is 21,680 even or odd?
Show the answer
Even
What is 21,680 + 10?
Show the answer
21,690
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 21,680 in words?
21,680 is written "twenty-one thousand six hundred and eighty".
Is 21,680 a prime number?
No. 21,680 is a composite number, because it has more than two factors.
What are the factors of 21,680?
The factors of 21,680 are 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 271, 542, 1,084, 1,355, 2,168, 2,710, 4,336, 5,420, 10,840 and 21,680.