The number 18315
18315 is a composite number with 24 divisors. Its prime factorisation is × 5 × 11 × 37. Divisors (24): 1, 3, 5, 9, 11, 15, 33, 37, 45, 55, 99, 111, 165, 185, 333, 407 … 18315.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18315: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18315 is composite. Its prime factorisation is
- 3
The divisors add up to 35568; without 18315 itself that is 17253, so 18315 is deficient (17253 is less than 18315). Euler's totient φ(18315) = 8640 numbers up to 18315 share no factor with it.
- 4
The digits of 18315 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 97 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18315 = 3^{2} \times 5 \times 11 \times 37 \]18315 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 35568 |
| Euler totient φ(n) | 8640 |
| Square | 335439225 |
| Cube | 6143569405875 |
| Square root | 135.332923 (= 3√2035) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 97 |
| Scientific notation | 1.8315 × |
18315 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand three hundred and fifteen |
| Binary (base 2) | 100011110001011 |
| Octal (base 8) | 43613 |
| Hexadecimal (base 16) | 478B |
| Base 3 | 221010100 |
| As time | 18315 seconds = 5 h 5 min 15 s |
Is 18315 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 (18315 ÷ 3 = 6105) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (18315 ÷ 5 = 3663) | 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 3) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (18315 ÷ 9 = 2035) | 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 | Yes (18315 ÷ 11 = 1665) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18315 a prime number?
No. 18315 = × 5 × 11 × 37, so it is divisible by 3.
What are the factors of 18315?
1, 3, 5, 9, 11, 15, 33, 37, 45, 55, 99, 111, 165, 185, 333, 407, 495, 555, 1221, 1665, 2035, 3663, 6105, 18315.
What is 18315 in binary?
100011110001011 (hexadecimal 478B, octal 43613).
What is the square root of 18315?
About 135.3329, exactly 3√2035.
Is 18315 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 18315?
18315 is a happy number: repeatedly adding the squares of its digits reaches 1.