The number 21339
21339 is a composite number with 6 divisors. Its prime factorisation is × 2371. Divisors (6): 1, 3, 9, 2371, 7113, 21339.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21339 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21339 is composite. Its prime factorisation is
- 3
The divisors add up to 30836; without 21339 itself that is 9497, so 21339 is deficient (9497 is less than 21339). Euler's totient φ(21339) = 14220 numbers up to 21339 share no factor with it.
- 4
The digits of 21339 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 87 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21339 = 3^{2} \times 2371 \]21339 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 30836 |
| Euler totient φ(n) | 14220 |
| Square | 455352921 |
| Cube | 9716775981219 |
| Square root | 146.078746 (= 3√2371) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.1339 × |
21339 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and thirty-nine |
| Binary (base 2) | 101001101011011 |
| Octal (base 8) | 51533 |
| Hexadecimal (base 16) | 535B |
| Base 3 | 1002021100 |
| As time | 21339 seconds = 5 h 55 min 39 s |
Is 21339 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21339 ÷ 3 = 7113) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21339 ÷ 9 = 2371) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21339 a prime number?
No. 21339 = × 2371, so it is divisible by 3.
What are the factors of 21339?
1, 3, 9, 2371, 7113, 21339.
What is 21339 in binary?
101001101011011 (hexadecimal 535B, octal 51533).
What is the square root of 21339?
About 146.0787, exactly 3√2371.
Is 21339 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 21339?
It is a composite number with 6 divisors.