The number 9909
9909 is a composite number with 8 divisors. Its prime factorisation is × 367. Divisors (8): 1, 3, 9, 27, 367, 1101, 3303, 9909.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 9909: a Harshad number: divisible by its digit sum 27.
- 2
9909 is composite. Its prime factorisation is
- 3
The divisors add up to 14720; without 9909 itself that is 4811, so 9909 is deficient (4811 is less than 9909). Euler's totient φ(9909) = 6588 numbers up to 9909 share no factor with it.
- 4
The digits of 9909 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 135 steps to reach 1.
LaTeX source of the formulas on this page
\[ 9909 = 3^{3} \times 367 \]9909 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 14720 |
| Euler totient φ(n) | 6588 |
| Square | 98188281 |
| Cube | 972947676429 |
| Square root | 99.543960 (= 3√1101) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 135 |
| Scientific notation | 9.909 × |
9909 in other forms
| Form | Value |
|---|---|
| In words | nine thousand nine hundred and nine |
| Binary (base 2) | 10011010110101 |
| Octal (base 8) | 23265 |
| Hexadecimal (base 16) | 26B5 |
| Base 3 | 111121000 |
| As time | 9909 seconds = 2 h 45 min 9 s |
Is 9909 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 (9909 ÷ 3 = 3303) | 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 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 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 | Yes (9909 ÷ 9 = 1101) | 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 9) | 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 9909 a prime number?
No. 9909 = × 367, so it is divisible by 3.
What are the factors of 9909?
1, 3, 9, 27, 367, 1101, 3303, 9909.
What is 9909 in binary?
10011010110101 (hexadecimal 26B5, octal 23265).
What is the square root of 9909?
About 99.5440, exactly 3√1101.
Is 9909 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 9909?
9909 is a Harshad number: divisible by its digit sum 27.