The number 18361
18361 is a composite number with 8 divisors. Its prime factorisation is 7 × 43 × 61. Divisors (8): 1, 7, 43, 61, 301, 427, 2623, 18361.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18361 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18361 is composite. Its prime factorisation is
- 3
The divisors add up to 21824; without 18361 itself that is 3463, so 18361 is deficient (3463 is less than 18361). Euler's totient φ(18361) = 15120 numbers up to 18361 share no factor with it.
- 4
The digits of 18361 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 61 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18361 = 7 \times 43 \times 61 \]
18361 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 21824 |
| Euler totient φ(n) | 15120 |
| Square | 337126321 |
| Cube | 6189976379881 |
| Square root | 135.502767 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 61 |
| Scientific notation | 1.8361 × |
18361 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand three hundred and sixty-one |
| Binary (base 2) | 100011110111001 |
| Octal (base 8) | 43671 |
| Hexadecimal (base 16) | 47B9 |
| Base 3 | 221012001 |
| As time | 18361 seconds = 5 h 6 min 1 s |
Is 18361 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 1) | 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 (18361 ÷ 7 = 2623) | 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 1) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 18361 a prime number?
No. 18361 = 7 × 43 × 61, so it is divisible by 7.
What are the factors of 18361?
1, 7, 43, 61, 301, 427, 2623, 18361.
What is 18361 in binary?
100011110111001 (hexadecimal 47B9, octal 43671).
What is the square root of 18361?
About 135.5028.
Is 18361 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 18361?
It is a composite number with 8 divisors.