The number 47728
47728 is a composite number with 20 divisors. Its prime factorisation is × 19 × 157. Divisors (20): 1, 2, 4, 8, 16, 19, 38, 76, 152, 157, 304, 314, 628, 1256, 2512, 2983 … 47728.
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How to work it out
- 1
47728 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
47728 is composite. Its prime factorisation is
- 3
The divisors add up to 97960; without 47728 itself that is 50232, so 47728 is abundant (50232 is more than 47728). Euler's totient φ(47728) = 22464 numbers up to 47728 share no factor with it.
- 4
The digits of 47728 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 145 steps to reach 1.
LaTeX source of the formulas on this page
\[ 47728 = 2^{4} \times 19 \times 157 \]47728 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 97960 |
| Euler totient φ(n) | 22464 |
| Square | 2277961984 |
| Cube | 108722569572352 |
| Square root | 218.467389 (= 4√2983) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 145 |
| Scientific notation | 4.7728 × |
47728 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand seven hundred and twenty-eight |
| Binary (base 2) | 1011101001110000 |
| Octal (base 8) | 135160 |
| Hexadecimal (base 16) | BA70 |
| Base 3 | 2102110201 |
| As time | 47728 seconds = 13 h 15 min 28 s |
Is 47728 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (47728 ÷ 2 = 23864) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (47728 ÷ 4 = 11932) | 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 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 (47728 ÷ 8 = 5966) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 47728 a prime number?
No. 47728 = × 19 × 157, so it is divisible by 2.
What are the factors of 47728?
1, 2, 4, 8, 16, 19, 38, 76, 152, 157, 304, 314, 628, 1256, 2512, 2983, 5966, 11932, 23864, 47728.
What is 47728 in binary?
1011101001110000 (hexadecimal BA70, octal 135160).
What is the square root of 47728?
About 218.4674, exactly 4√2983.
Is 47728 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 47728?
It is a composite number with 20 divisors.