The number 20804
20804 is a composite number with 12 divisors. Its prime factorisation is × 7 × 743. Divisors (12): 1, 2, 4, 7, 14, 28, 743, 1486, 2972, 5201, 10402, 20804.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20804: a Harshad number: divisible by its digit sum 14.
- 2
20804 is composite. Its prime factorisation is
- 3
The divisors add up to 41664; without 20804 itself that is 20860, so 20804 is abundant (20860 is more than 20804). Euler's totient φ(20804) = 8904 numbers up to 20804 share no factor with it.
- 4
The digits of 20804 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 149 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20804 = 2^{2} \times 7 \times 743 \]20804 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 41664 |
| Euler totient φ(n) | 8904 |
| Square | 432806416 |
| Cube | 9004104678464 |
| Square root | 144.235918 (= 2√5201) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 149 |
| Scientific notation | 2.0804 × |
20804 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand eight hundred and four |
| Binary (base 2) | 101000101000100 |
| Octal (base 8) | 50504 |
| Hexadecimal (base 16) | 5144 |
| Base 3 | 1001112112 |
| As time | 20804 seconds = 5 h 46 min 44 s |
Is 20804 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20804 ÷ 2 = 10402) | 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 (20804 ÷ 4 = 5201) | 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 | Yes (20804 ÷ 7 = 2972) | 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 5) | 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 3) | 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 20804 a prime number?
No. 20804 = × 7 × 743, so it is divisible by 2.
What are the factors of 20804?
1, 2, 4, 7, 14, 28, 743, 1486, 2972, 5201, 10402, 20804.
What is 20804 in binary?
101000101000100 (hexadecimal 5144, octal 50504).
What is the square root of 20804?
About 144.2359, exactly 2√5201.
Is 20804 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 20804?
20804 is a Harshad number: divisible by its digit sum 14.