The number 18011
18011 is a composite number with 8 divisors. Its prime factorisation is 7 × 31 × 83. Divisors (8): 1, 7, 31, 83, 217, 581, 2573, 18011.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18011 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18011 is composite. Its prime factorisation is
- 3
The divisors add up to 21504; without 18011 itself that is 3493, so 18011 is deficient (3493 is less than 18011). Euler's totient φ(18011) = 14760 numbers up to 18011 share no factor with it.
- 4
The digits of 18011 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 66 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18011 = 7 \times 31 \times 83 \]
18011 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 21504 |
| Euler totient φ(n) | 14760 |
| Square | 324396121 |
| Cube | 5842698535331 |
| Square root | 134.205067 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 66 |
| Scientific notation | 1.8011 × |
18011 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand and eleven |
| Binary (base 2) | 100011001011011 |
| Octal (base 8) | 43133 |
| Hexadecimal (base 16) | 465B |
| Base 3 | 220201002 |
| As time | 18011 seconds = 5 h 0 min 11 s |
Is 18011 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 | Yes (18011 ÷ 7 = 2573) | 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 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18011 a prime number?
No. 18011 = 7 × 31 × 83, so it is divisible by 7.
What are the factors of 18011?
1, 7, 31, 83, 217, 581, 2573, 18011.
What is 18011 in binary?
100011001011011 (hexadecimal 465B, octal 43133).
What is the square root of 18011?
About 134.2051.
Is 18011 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 18011?
It is a composite number with 8 divisors.