The number 13865
13865 is a composite number with 8 divisors. Its prime factorisation is 5 × 47 × 59. Divisors (8): 1, 5, 47, 59, 235, 295, 2773, 13865.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
13865 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
13865 is composite. Its prime factorisation is
- 3
The divisors add up to 17280; without 13865 itself that is 3415, so 13865 is deficient (3415 is less than 13865). Euler's totient φ(13865) = 10672 numbers up to 13865 share no factor with it.
- 4
The digits of 13865 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 89 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13865 = 5 \times 47 \times 59 \]
13865 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 17280 |
| Euler totient φ(n) | 10672 |
| Square | 192238225 |
| Cube | 2665382989625 |
| Square root | 117.749735 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 89 |
| Scientific notation | 1.3865 × |
13865 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand eight hundred and sixty-five |
| Binary (base 2) | 11011000101001 |
| Octal (base 8) | 33051 |
| Hexadecimal (base 16) | 3629 |
| Base 3 | 201000112 |
| As time | 13865 seconds = 3 h 51 min 5 s |
Is 13865 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 (13865 ÷ 5 = 2773) | 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 | No (remainder 5) | 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 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 5) | 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 13865 a prime number?
No. 13865 = 5 × 47 × 59, so it is divisible by 5.
What are the factors of 13865?
1, 5, 47, 59, 235, 295, 2773, 13865.
What is 13865 in binary?
11011000101001 (hexadecimal 3629, octal 33051).
What is the square root of 13865?
About 117.7497.
Is 13865 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 13865?
It is a composite number with 8 divisors.