The number 18109
18109 is a composite number with 8 divisors. Its prime factorisation is 7 × 13 × 199. Divisors (8): 1, 7, 13, 91, 199, 1393, 2587, 18109.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18109 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18109 is composite. Its prime factorisation is
- 3
The divisors add up to 22400; without 18109 itself that is 4291, so 18109 is deficient (4291 is less than 18109). Euler's totient φ(18109) = 14256 numbers up to 18109 share no factor with it.
- 4
The digits of 18109 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18109 = 7 \times 13 \times 199 \]
18109 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 22400 |
| Euler totient φ(n) | 14256 |
| Square | 327935881 |
| Cube | 5938590869029 |
| Square root | 134.569685 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 40 |
| Scientific notation | 1.8109 × |
18109 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand one hundred and nine |
| Binary (base 2) | 100011010111101 |
| Octal (base 8) | 43275 |
| Hexadecimal (base 16) | 46BD |
| Base 3 | 220211201 |
| As time | 18109 seconds = 5 h 1 min 49 s |
Is 18109 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 | Yes (18109 ÷ 7 = 2587) | 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 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18109 a prime number?
No. 18109 = 7 × 13 × 199, so it is divisible by 7.
What are the factors of 18109?
1, 7, 13, 91, 199, 1393, 2587, 18109.
What is 18109 in binary?
100011010111101 (hexadecimal 46BD, octal 43275).
What is the square root of 18109?
About 134.5697.
Is 18109 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 18109?
It is a composite number with 8 divisors.