The number 13845
13845 is a composite number with 16 divisors. Its prime factorisation is 3 × 5 × 13 × 71. Divisors (16): 1, 3, 5, 13, 15, 39, 65, 71, 195, 213, 355, 923, 1065, 2769, 4615, 13845.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
13845 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
13845 is composite. Its prime factorisation is
- 3
The divisors add up to 24192; without 13845 itself that is 10347, so 13845 is deficient (10347 is less than 13845). Euler's totient φ(13845) = 6720 numbers up to 13845 share no factor with it.
- 4
The digits of 13845 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 151 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13845 = 3 \times 5 \times 13 \times 71 \]
13845 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 24192 |
| Euler totient φ(n) | 6720 |
| Square | 191684025 |
| Cube | 2653865326125 |
| Square root | 117.664778 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 151 |
| Scientific notation | 1.3845 × |
13845 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand eight hundred and forty-five |
| Binary (base 2) | 11011000010101 |
| Octal (base 8) | 33025 |
| Hexadecimal (base 16) | 3615 |
| Base 3 | 200222210 |
| As time | 13845 seconds = 3 h 50 min 45 s |
Is 13845 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 (13845 ÷ 3 = 4615) | 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 (13845 ÷ 5 = 2769) | 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 6) | 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 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 7) | 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 13845 a prime number?
No. 13845 = 3 × 5 × 13 × 71, so it is divisible by 3.
What are the factors of 13845?
1, 3, 5, 13, 15, 39, 65, 71, 195, 213, 355, 923, 1065, 2769, 4615, 13845.
What is 13845 in binary?
11011000010101 (hexadecimal 3615, octal 33025).
What is the square root of 13845?
About 117.6648.
Is 13845 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 13845?
It is a composite number with 16 divisors.