The number 28808
28808 is a composite number with 16 divisors. Its prime factorisation is × 13 × 277. Divisors (16): 1, 2, 4, 8, 13, 26, 52, 104, 277, 554, 1108, 2216, 3601, 7202, 14404, 28808.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28808: a Harshad number: divisible by its digit sum 26.
- 2
28808 is composite. Its prime factorisation is
- 3
The divisors add up to 58380; without 28808 itself that is 29572, so 28808 is abundant (29572 is more than 28808). Euler's totient φ(28808) = 13248 numbers up to 28808 share no factor with it.
- 4
The digits of 28808 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 121 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28808 = 2^{3} \times 13 \times 277 \]28808 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 58380 |
| Euler totient φ(n) | 13248 |
| Square | 829900864 |
| Cube | 23907784090112 |
| Square root | 169.729196 (= 2√7202) |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 121 |
| Scientific notation | 2.8808 × |
28808 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand eight hundred and eight |
| Binary (base 2) | 111000010001000 |
| Octal (base 8) | 70210 |
| Hexadecimal (base 16) | 7088 |
| Base 3 | 1110111222 |
| As time | 28808 seconds = 8 h 0 min 8 s |
Is 28808 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28808 ÷ 2 = 14404) | 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 (28808 ÷ 4 = 7202) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 3) | 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 (28808 ÷ 8 = 3601) | 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 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 28808 a prime number?
No. 28808 = × 13 × 277, so it is divisible by 2.
What are the factors of 28808?
1, 2, 4, 8, 13, 26, 52, 104, 277, 554, 1108, 2216, 3601, 7202, 14404, 28808.
What is 28808 in binary?
111000010001000 (hexadecimal 7088, octal 70210).
What is the square root of 28808?
About 169.7292, exactly 2√7202.
Is 28808 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 28808?
28808 is a Harshad number: divisible by its digit sum 26.