21,980 in words
21,980
twenty-one thousand nine hundred and eighty
21,980 is written twenty-one thousand nine hundred and eighty.
Ways to write it
- As an ordinal
- twenty-one thousand nine hundred and eightieth
- Expanded form
- 20,000 + 1,000 + 900 + 80
Place value
| Place | Digit | Value |
|---|---|---|
| ten thousands | 2 | 20,000 |
| thousands | 1 | 1,000 |
| hundreds | 9 | 900 |
| tens | 8 | 80 |
| ones | 0 | 0 |
Number facts
- Even or odd
- Even
- Prime or composite
- Composite
- Factors
- 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140, 157, 314, 628, 785, 1,099, 1,570, 2,198, 3,140, 4,396, 5,495, 10,990 and 21,980 (24 factors)
- First 10 multiples
- 21,980, 43,960, 65,940, 87,920, 109,900, 131,880, 153,860, 175,840, 197,820, 219,800
- Square
- 21,980 × 21,980 = 483,120,400
- Square root
- ≈ 148.26
- Sum of the digits
- 2 + 1 + 9 + 8 + 0 = 20
- Rounded to the nearest 10
- 21,980
- Rounded to the nearest 100
- 22,000
- Rounded to the nearest 1000
- 22,000
- Number before
- 21,979
- Number after
- 21,981
- In binary
101010111011100
Quick check
What number comes just after 21,980?
Show the answer
21,981
Is 21,980 even or odd?
Show the answer
Even
What is 21,980 + 10?
Show the answer
21,990
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 21,980 in words?
21,980 is written "twenty-one thousand nine hundred and eighty".
Is 21,980 a prime number?
No. 21,980 is a composite number, because it has more than two factors.
What are the factors of 21,980?
The factors of 21,980 are 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140, 157, 314, 628, 785, 1,099, 1,570, 2,198, 3,140, 4,396, 5,495, 10,990 and 21,980.