The number 21333
21333 is a composite number with 8 divisors. Its prime factorisation is 3 × 13 × 547. Divisors (8): 1, 3, 13, 39, 547, 1641, 7111, 21333.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21333: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
21333 is composite. Its prime factorisation is
- 3
The divisors add up to 30688; without 21333 itself that is 9355, so 21333 is deficient (9355 is less than 21333). Euler's totient φ(21333) = 13104 numbers up to 21333 share no factor with it.
- 4
The digits of 21333 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 118 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21333 = 3 \times 13 \times 547 \]
21333 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 30688 |
| Euler totient φ(n) | 13104 |
| Square | 455096889 |
| Cube | 9708581933037 |
| Square root | 146.058208 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 118 |
| Scientific notation | 2.1333 × |
21333 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and thirty-three |
| Binary (base 2) | 101001101010101 |
| Octal (base 8) | 51525 |
| Hexadecimal (base 16) | 5355 |
| Base 3 | 1002021010 |
| As time | 21333 seconds = 5 h 55 min 33 s |
Is 21333 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 (21333 ÷ 3 = 7111) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 4) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21333 a prime number?
No. 21333 = 3 × 13 × 547, so it is divisible by 3.
What are the factors of 21333?
1, 3, 13, 39, 547, 1641, 7111, 21333.
What is 21333 in binary?
101001101010101 (hexadecimal 5355, octal 51525).
What is the square root of 21333?
About 146.0582.
Is 21333 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 21333?
21333 is a happy number: repeatedly adding the squares of its digits reaches 1.