The number 18015
18015 is a composite number with 8 divisors. Its prime factorisation is 3 × 5 × 1201. Divisors (8): 1, 3, 5, 15, 1201, 3603, 6005, 18015.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18015: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 15.
- 2
18015 is composite. Its prime factorisation is
- 3
The divisors add up to 28848; without 18015 itself that is 10833, so 18015 is deficient (10833 is less than 18015). Euler's totient φ(18015) = 9600 numbers up to 18015 share no factor with it.
- 4
The digits of 18015 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 79 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18015 = 3 \times 5 \times 1201 \]
18015 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 28848 |
| Euler totient φ(n) | 9600 |
| Square | 324540225 |
| Cube | 5846592153375 |
| Square root | 134.219969 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 79 |
| Scientific notation | 1.8015 × |
18015 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand and fifteen |
| Binary (base 2) | 100011001011111 |
| Octal (base 8) | 43137 |
| Hexadecimal (base 16) | 465F |
| Base 3 | 220201020 |
| As time | 18015 seconds = 5 h 0 min 15 s |
Is 18015 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 (18015 ÷ 3 = 6005) | 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 (18015 ÷ 5 = 3603) | 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 4) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | 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 8) | 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 18015 a prime number?
No. 18015 = 3 × 5 × 1201, so it is divisible by 3.
What are the factors of 18015?
1, 3, 5, 15, 1201, 3603, 6005, 18015.
What is 18015 in binary?
100011001011111 (hexadecimal 465F, octal 43137).
What is the square root of 18015?
About 134.2200.
Is 18015 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 18015?
18015 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 15.