The number 2808
2808 is a composite number with 32 divisors. Its prime factorisation is × × 13. Divisors (32): 1, 2, 3, 4, 6, 8, 9, 12, 13, 18, 24, 26, 27, 36, 39, 52 … 2808.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2808: a Harshad number: divisible by its digit sum 18.
- 2
2808 is composite. Its prime factorisation is
- 3
The divisors add up to 8400; without 2808 itself that is 5592, so 2808 is abundant (5592 is more than 2808). Euler's totient φ(2808) = 864 numbers up to 2808 share no factor with it.
- 4
The digits of 2808 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 84 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2808 = 2^{3} \times 3^{3} \times 13 \]2808 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 8400 |
| Euler totient φ(n) | 864 |
| Square | 7884864 |
| Cube | 22140698112 |
| Square root | 52.990565 (= 6√78) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 84 |
| Scientific notation | 2.808 × |
2808 in other forms
| Form | Value |
|---|---|
| In words | two thousand eight hundred and eight |
| Roman numerals | MMDCCCVIII |
| Binary (base 2) | 101011111000 |
| Octal (base 8) | 5370 |
| Hexadecimal (base 16) | AF8 |
| Base 3 | 10212000 |
| As time | 2808 seconds = 46 min 48 s |
Is 2808 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (2808 ÷ 2 = 1404) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (2808 ÷ 3 = 936) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (2808 ÷ 4 = 702) | 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 | Yes (2808 ÷ 6 = 468) | 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 | Yes (2808 ÷ 8 = 351) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (2808 ÷ 9 = 312) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (2808 ÷ 12 = 234) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2808 a prime number?
No. 2808 = × × 13, so it is divisible by 2.
What are the factors of 2808?
1, 2, 3, 4, 6, 8, 9, 12, 13, 18, 24, 26, 27, 36, 39, 52, 54, 72, 78, 104, 108, 117, 156, 216, 234, 312, 351, 468, 702, 936, 1404, 2808.
What is 2808 in binary?
101011111000 (hexadecimal AF8, octal 5370).
What is the square root of 2808?
About 52.9906, exactly 6√78.
What is 2808 in Roman numerals?
MMDCCCVIII.
Is 2808 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 2808?
2808 is a Harshad number: divisible by its digit sum 18.