The number 18404
18404 is a composite number with 12 divisors. Its prime factorisation is × 43 × 107. Divisors (12): 1, 2, 4, 43, 86, 107, 172, 214, 428, 4601, 9202, 18404.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18404: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18404 is composite. Its prime factorisation is
- 3
The divisors add up to 33264; without 18404 itself that is 14860, so 18404 is deficient (14860 is less than 18404). Euler's totient φ(18404) = 8904 numbers up to 18404 share no factor with it.
- 4
The digits of 18404 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 61 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18404 = 2^{2} \times 43 \times 107 \]18404 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 33264 |
| Euler totient φ(n) | 8904 |
| Square | 338707216 |
| Cube | 6233567603264 |
| Square root | 135.661343 (= 2√4601) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 61 |
| Scientific notation | 1.8404 × |
18404 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand four hundred and four |
| Binary (base 2) | 100011111100100 |
| Octal (base 8) | 43744 |
| Hexadecimal (base 16) | 47E4 |
| Base 3 | 221020122 |
| As time | 18404 seconds = 5 h 6 min 44 s |
Is 18404 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18404 ÷ 2 = 9202) | 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 | Yes (18404 ÷ 4 = 4601) | 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 2) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18404 a prime number?
No. 18404 = × 43 × 107, so it is divisible by 2.
What are the factors of 18404?
1, 2, 4, 43, 86, 107, 172, 214, 428, 4601, 9202, 18404.
What is 18404 in binary?
100011111100100 (hexadecimal 47E4, octal 43744).
What is the square root of 18404?
About 135.6613, exactly 2√4601.
Is 18404 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 18404?
18404 is a happy number: repeatedly adding the squares of its digits reaches 1.