The number 13685
13685 is a composite number with 16 divisors. Its prime factorisation is 5 × 7 × 17 × 23. Divisors (16): 1, 5, 7, 17, 23, 35, 85, 115, 119, 161, 391, 595, 805, 1955, 2737, 13685.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13685: a Harshad number: divisible by its digit sum 23.
- 2
13685 is composite. Its prime factorisation is
- 3
The divisors add up to 20736; without 13685 itself that is 7051, so 13685 is deficient (7051 is less than 13685). Euler's totient φ(13685) = 8448 numbers up to 13685 share no factor with it.
- 4
The digits of 13685 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13685 = 5 \times 7 \times 17 \times 23 \]
13685 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 20736 |
| Euler totient φ(n) | 8448 |
| Square | 187279225 |
| Cube | 2562916194125 |
| Square root | 116.982905 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 58 |
| Scientific notation | 1.3685 × |
13685 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand six hundred and eighty-five |
| Binary (base 2) | 11010101110101 |
| Octal (base 8) | 32565 |
| Hexadecimal (base 16) | 3575 |
| Base 3 | 200202212 |
| As time | 13685 seconds = 3 h 48 min 5 s |
Is 13685 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 | No (remainder 2) | 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 (13685 ÷ 5 = 2737) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (13685 ÷ 7 = 1955) | 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 5) | 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 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 13685 a prime number?
No. 13685 = 5 × 7 × 17 × 23, so it is divisible by 5.
What are the factors of 13685?
1, 5, 7, 17, 23, 35, 85, 115, 119, 161, 391, 595, 805, 1955, 2737, 13685.
What is 13685 in binary?
11010101110101 (hexadecimal 3575, octal 32565).
What is the square root of 13685?
About 116.9829.
Is 13685 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 13685?
13685 is a Harshad number: divisible by its digit sum 23.