The number 18187
18187 is a composite number with 4 divisors. Its prime factorisation is 13 × 1399. Divisors (4): 1, 13, 1399, 18187.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18187: a semiprime: 13 × 1399, the product of two primes.
- 2
18187 is composite. Its prime factorisation is
- 3
The divisors add up to 19600; without 18187 itself that is 1413, so 18187 is deficient (1413 is less than 18187). Euler's totient φ(18187) = 16776 numbers up to 18187 share no factor with it.
- 4
The digits of 18187 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 66 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18187 = 13 \times 1399 \]
18187 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 19600 |
| Euler totient φ(n) | 16776 |
| Square | 330766969 |
| Cube | 6015658865203 |
| Square root | 134.859186 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 66 |
| Scientific notation | 1.8187 × |
18187 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand one hundred and eighty-seven |
| Binary (base 2) | 100011100001011 |
| Octal (base 8) | 43413 |
| Hexadecimal (base 16) | 470B |
| Base 3 | 220221121 |
| As time | 18187 seconds = 5 h 3 min 7 s |
Is 18187 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 1) | 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 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18187 a prime number?
No. 18187 = 13 × 1399, so it is divisible by 13.
What are the factors of 18187?
1, 13, 1399, 18187.
What is 18187 in binary?
100011100001011 (hexadecimal 470B, octal 43413).
What is the square root of 18187?
About 134.8592.
Is 18187 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 18187?
18187 is a semiprime: 13 × 1399, the product of two primes.