The number 55728
55728 is a composite number with 50 divisors. Its prime factorisation is × × 43. Divisors (50): 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 27, 36, 43, 48, 54 … 55728.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55728: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 27.
- 2
55728 is composite. Its prime factorisation is
- 3
The divisors add up to 165044; without 55728 itself that is 109316, so 55728 is abundant (109316 is more than 55728). Euler's totient φ(55728) = 18144 numbers up to 55728 share no factor with it.
- 4
The digits of 55728 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 91 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55728 = 2^{4} \times 3^{4} \times 43 \]55728 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 50 |
| Sum of divisors | 165044 |
| Euler totient φ(n) | 18144 |
| Square | 3105609984 |
| Cube | 173069433188352 |
| Square root | 236.067787 (= 36√43) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 91 |
| Scientific notation | 5.5728 × |
55728 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand seven hundred and twenty-eight |
| Binary (base 2) | 1101100110110000 |
| Octal (base 8) | 154660 |
| Hexadecimal (base 16) | D9B0 |
| Base 3 | 2211110000 |
| As time | 55728 seconds = 15 h 28 min 48 s |
Is 55728 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (55728 ÷ 2 = 27864) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (55728 ÷ 3 = 18576) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (55728 ÷ 4 = 13932) | 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 (55728 ÷ 6 = 9288) | 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 (55728 ÷ 8 = 6966) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (55728 ÷ 9 = 6192) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (55728 ÷ 12 = 4644) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 55728 a prime number?
No. 55728 = × × 43, so it is divisible by 2.
What are the factors of 55728?
1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 27, 36, 43, 48, 54, 72, 81, 86, 108, 129, 144, 162, 172, 216, 258, 324, 344, 387, 432, 516, 648, 688, 774, 1032, 1161, 1296, 1548, 2064, 2322, 3096, 3483, 4644, 6192, 6966, 9288, 13932, 18576, 27864, 55728.
What is 55728 in binary?
1101100110110000 (hexadecimal D9B0, octal 154660).
What is the square root of 55728?
About 236.0678, exactly 36√43.
Is 55728 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 55728?
55728 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 27.