The number 18400
18400 is a composite number with 36 divisors. Its prime factorisation is × × 23. Divisors (36): 1, 2, 4, 5, 8, 10, 16, 20, 23, 25, 32, 40, 46, 50, 80, 92 … 18400.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18400 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18400 is composite. Its prime factorisation is
- 3
The divisors add up to 46872; without 18400 itself that is 28472, so 18400 is abundant (28472 is more than 18400). Euler's totient φ(18400) = 7040 numbers up to 18400 share no factor with it.
- 4
The digits of 18400 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18400 = 2^{5} \times 5^{2} \times 23 \]18400 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 46872 |
| Euler totient φ(n) | 7040 |
| Square | 338560000 |
| Cube | 6229504000000 |
| Square root | 135.646600 (= 20√46) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 48 |
| Scientific notation | 1.84 × |
18400 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand four hundred |
| Binary (base 2) | 100011111100000 |
| Octal (base 8) | 43740 |
| Hexadecimal (base 16) | 47E0 |
| Base 3 | 221020111 |
| As time | 18400 seconds = 5 h 6 min 40 s |
Is 18400 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18400 ÷ 2 = 9200) | 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 | Yes (18400 ÷ 4 = 4600) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (18400 ÷ 5 = 3680) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 | Yes (18400 ÷ 8 = 2300) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (18400 ÷ 10 = 1840) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18400 a prime number?
No. 18400 = × × 23, so it is divisible by 2.
What are the factors of 18400?
1, 2, 4, 5, 8, 10, 16, 20, 23, 25, 32, 40, 46, 50, 80, 92, 100, 115, 160, 184, 200, 230, 368, 400, 460, 575, 736, 800, 920, 1150, 1840, 2300, 3680, 4600, 9200, 18400.
What is 18400 in binary?
100011111100000 (hexadecimal 47E0, octal 43740).
What is the square root of 18400?
About 135.6466, exactly 20√46.
Is 18400 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 18400?
It is a composite number with 36 divisors.