The number 15005
15005 is a composite number with 4 divisors. Its prime factorisation is 5 × 3001. Divisors (4): 1, 5, 3001, 15005.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15005: a semiprime: 5 × 3001, the product of two primes.
- 2
15005 is composite. Its prime factorisation is
- 3
The divisors add up to 18012; without 15005 itself that is 3007, so 15005 is deficient (3007 is less than 15005). Euler's totient φ(15005) = 12000 numbers up to 15005 share no factor with it.
- 4
The digits of 15005 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15005 = 5 \times 3001 \]
15005 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 18012 |
| Euler totient φ(n) | 12000 |
| Square | 225150025 |
| Cube | 3378376125125 |
| Square root | 122.494898 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 63 |
| Scientific notation | 1.5005 × |
15005 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand and five |
| Binary (base 2) | 11101010011101 |
| Octal (base 8) | 35235 |
| Hexadecimal (base 16) | 3A9D |
| Base 3 | 202120202 |
| As time | 15005 seconds = 4 h 10 min 5 s |
Is 15005 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 (15005 ÷ 5 = 3001) | 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 15005 a prime number?
No. 15005 = 5 × 3001, so it is divisible by 5.
What are the factors of 15005?
1, 5, 3001, 15005.
What is 15005 in binary?
11101010011101 (hexadecimal 3A9D, octal 35235).
What is the square root of 15005?
About 122.4949.
Is 15005 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 15005?
15005 is a semiprime: 5 × 3001, the product of two primes.