The number 13665
13665 is a composite number with 8 divisors. Its prime factorisation is 3 × 5 × 911. Divisors (8): 1, 3, 5, 15, 911, 2733, 4555, 13665.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
13665 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
13665 is composite. Its prime factorisation is
- 3
The divisors add up to 21888; without 13665 itself that is 8223, so 13665 is deficient (8223 is less than 13665). Euler's totient φ(13665) = 7280 numbers up to 13665 share no factor with it.
- 4
The digits of 13665 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13665 = 3 \times 5 \times 911 \]
13665 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 21888 |
| Euler totient φ(n) | 7280 |
| Square | 186732225 |
| Cube | 2551695854625 |
| Square root | 116.897391 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 63 |
| Scientific notation | 1.3665 × |
13665 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand six hundred and sixty-five |
| Binary (base 2) | 11010101100001 |
| Octal (base 8) | 32541 |
| Hexadecimal (base 16) | 3561 |
| Base 3 | 200202010 |
| As time | 13665 seconds = 3 h 47 min 45 s |
Is 13665 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 (13665 ÷ 3 = 4555) | 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 | Yes (13665 ÷ 5 = 2733) | 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 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 1) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | 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 13665 a prime number?
No. 13665 = 3 × 5 × 911, so it is divisible by 3.
What are the factors of 13665?
1, 3, 5, 15, 911, 2733, 4555, 13665.
What is 13665 in binary?
11010101100001 (hexadecimal 3561, octal 32541).
What is the square root of 13665?
About 116.8974.
Is 13665 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 13665?
It is a composite number with 8 divisors.