The number 18005
18005 is a composite number with 8 divisors. Its prime factorisation is 5 × 13 × 277. Divisors (8): 1, 5, 13, 65, 277, 1385, 3601, 18005.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18005 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18005 is composite. Its prime factorisation is
- 3
The divisors add up to 23352; without 18005 itself that is 5347, so 18005 is deficient (5347 is less than 18005). Euler's totient φ(18005) = 13248 numbers up to 18005 share no factor with it.
- 4
The digits of 18005 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18005 = 5 \times 13 \times 277 \]
18005 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 23352 |
| Euler totient φ(n) | 13248 |
| Square | 324180025 |
| Cube | 5836861350125 |
| Square root | 134.182711 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 48 |
| Scientific notation | 1.8005 × |
18005 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand and five |
| Binary (base 2) | 100011001010101 |
| Octal (base 8) | 43125 |
| Hexadecimal (base 16) | 4655 |
| Base 3 | 220200212 |
| As time | 18005 seconds = 5 h 0 min 5 s |
Is 18005 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 (18005 ÷ 5 = 3601) | 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 1) | 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 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 9) | 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 18005 a prime number?
No. 18005 = 5 × 13 × 277, so it is divisible by 5.
What are the factors of 18005?
1, 5, 13, 65, 277, 1385, 3601, 18005.
What is 18005 in binary?
100011001010101 (hexadecimal 4655, octal 43125).
What is the square root of 18005?
About 134.1827.
Is 18005 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 18005?
It is a composite number with 8 divisors.