The number 18800
18800 is a composite number with 30 divisors. Its prime factorisation is × × 47. Divisors (30): 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 47, 50, 80, 94, 100, 188 … 18800.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18800: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18800 is composite. Its prime factorisation is
- 3
The divisors add up to 46128; without 18800 itself that is 27328, so 18800 is abundant (27328 is more than 18800). Euler's totient φ(18800) = 7360 numbers up to 18800 share no factor with it.
- 4
The digits of 18800 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 123 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18800 = 2^{4} \times 5^{2} \times 47 \]18800 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 30 |
| Sum of divisors | 46128 |
| Euler totient φ(n) | 7360 |
| Square | 353440000 |
| Cube | 6644672000000 |
| Square root | 137.113092 (= 20√47) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 123 |
| Scientific notation | 1.88 × |
18800 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand eight hundred |
| Binary (base 2) | 100100101110000 |
| Octal (base 8) | 44560 |
| Hexadecimal (base 16) | 4970 |
| Base 3 | 221210022 |
| As time | 18800 seconds = 5 h 13 min 20 s |
Is 18800 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18800 ÷ 2 = 9400) | 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 (18800 ÷ 4 = 4700) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (18800 ÷ 5 = 3760) | 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 5) | 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 (18800 ÷ 8 = 2350) | 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 | Yes (18800 ÷ 10 = 1880) | 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 18800 a prime number?
No. 18800 = × × 47, so it is divisible by 2.
What are the factors of 18800?
1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 47, 50, 80, 94, 100, 188, 200, 235, 376, 400, 470, 752, 940, 1175, 1880, 2350, 3760, 4700, 9400, 18800.
What is 18800 in binary?
100100101110000 (hexadecimal 4970, octal 44560).
What is the square root of 18800?
About 137.1131, exactly 20√47.
Is 18800 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 18800?
18800 is a happy number: repeatedly adding the squares of its digits reaches 1.