The number 21330
21330 is a composite number with 32 divisors. Its prime factorisation is 2 × × 5 × 79. Divisors (32): 1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 79, 90, 135 … 21330.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21330: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.
- 2
21330 is composite. Its prime factorisation is
- 3
The divisors add up to 57600; without 21330 itself that is 36270, so 21330 is abundant (36270 is more than 21330). Euler's totient φ(21330) = 5616 numbers up to 21330 share no factor with it.
- 4
The digits of 21330 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21330 = 2 \times 3^{3} \times 5 \times 79 \]21330 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 57600 |
| Euler totient φ(n) | 5616 |
| Square | 454968900 |
| Cube | 9704486637000 |
| Square root | 146.047937 (= 3√2370) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.133 × |
21330 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and thirty |
| Binary (base 2) | 101001101010010 |
| Octal (base 8) | 51522 |
| Hexadecimal (base 16) | 5352 |
| Base 3 | 1002021000 |
| As time | 21330 seconds = 5 h 55 min 30 s |
Is 21330 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21330 ÷ 2 = 10665) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21330 ÷ 3 = 7110) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21330 ÷ 5 = 4266) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21330 ÷ 6 = 3555) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21330 ÷ 9 = 2370) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (21330 ÷ 10 = 2133) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21330 a prime number?
No. 21330 = 2 × × 5 × 79, so it is divisible by 2.
What are the factors of 21330?
1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 79, 90, 135, 158, 237, 270, 395, 474, 711, 790, 1185, 1422, 2133, 2370, 3555, 4266, 7110, 10665, 21330.
What is 21330 in binary?
101001101010010 (hexadecimal 5352, octal 51522).
What is the square root of 21330?
About 146.0479, exactly 3√2370.
Is 21330 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 21330?
21330 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.