The number 18801
18801 is a composite number with 6 divisors. Its prime factorisation is × 2089. Divisors (6): 1, 3, 9, 2089, 6267, 18801.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18801: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18801 is composite. Its prime factorisation is
- 3
The divisors add up to 27170; without 18801 itself that is 8369, so 18801 is deficient (8369 is less than 18801). Euler's totient φ(18801) = 12528 numbers up to 18801 share no factor with it.
- 4
The digits of 18801 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 123 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18801 = 3^{2} \times 2089 \]18801 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 27170 |
| Euler totient φ(n) | 12528 |
| Square | 353477601 |
| Cube | 6645732376401 |
| Square root | 137.116739 (= 3√2089) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 123 |
| Scientific notation | 1.8801 × |
18801 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand eight hundred and one |
| Binary (base 2) | 100100101110001 |
| Octal (base 8) | 44561 |
| Hexadecimal (base 16) | 4971 |
| Base 3 | 221210100 |
| As time | 18801 seconds = 5 h 13 min 21 s |
Is 18801 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 | Yes (18801 ÷ 3 = 6267) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 | Yes (18801 ÷ 9 = 2089) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18801 a prime number?
No. 18801 = × 2089, so it is divisible by 3.
What are the factors of 18801?
1, 3, 9, 2089, 6267, 18801.
What is 18801 in binary?
100100101110001 (hexadecimal 4971, octal 44561).
What is the square root of 18801?
About 137.1167, exactly 3√2089.
Is 18801 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 18801?
18801 is a happy number: repeatedly adding the squares of its digits reaches 1.