The number 28736
28736 is a composite number with 14 divisors. Its prime factorisation is × 449. Divisors (14): 1, 2, 4, 8, 16, 32, 64, 449, 898, 1796, 3592, 7184, 14368, 28736.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
28736 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
28736 is composite. Its prime factorisation is
- 3
The divisors add up to 57150; without 28736 itself that is 28414, so 28736 is deficient (28414 is less than 28736). Euler's totient φ(28736) = 14336 numbers up to 28736 share no factor with it.
- 4
The digits of 28736 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
\[ 28736 = 2^{6} \times 449 \]28736 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 14 |
| Sum of divisors | 57150 |
| Euler totient φ(n) | 14336 |
| Square | 825757696 |
| Cube | 23728973152256 |
| Square root | 169.516961 (= 8√449) |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 121 |
| Scientific notation | 2.8736 × |
28736 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand seven hundred and thirty-six |
| Binary (base 2) | 111000001000000 |
| Octal (base 8) | 70100 |
| Hexadecimal (base 16) | 7040 |
| Base 3 | 1110102022 |
| As time | 28736 seconds = 7 h 58 min 56 s |
Is 28736 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28736 ÷ 2 = 14368) | 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 (28736 ÷ 4 = 7184) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 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 (28736 ÷ 8 = 3592) | 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 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 28736 a prime number?
No. 28736 = × 449, so it is divisible by 2.
What are the factors of 28736?
1, 2, 4, 8, 16, 32, 64, 449, 898, 1796, 3592, 7184, 14368, 28736.
What is 28736 in binary?
111000001000000 (hexadecimal 7040, octal 70100).
What is the square root of 28736?
About 169.5170, exactly 8√449.
Is 28736 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 28736?
It is a composite number with 14 divisors.