The number 47128
47128 is a composite number with 16 divisors. Its prime factorisation is × 43 × 137. Divisors (16): 1, 2, 4, 8, 43, 86, 137, 172, 274, 344, 548, 1096, 5891, 11782, 23564, 47128.
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How to work it out
- 1
47128 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
47128 is composite. Its prime factorisation is
- 3
The divisors add up to 91080; without 47128 itself that is 43952, so 47128 is deficient (43952 is less than 47128). Euler's totient φ(47128) = 22848 numbers up to 47128 share no factor with it.
- 4
The digits of 47128 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 83 steps to reach 1.
LaTeX source of the formulas on this page
\[ 47128 = 2^{3} \times 43 \times 137 \]47128 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 91080 |
| Euler totient φ(n) | 22848 |
| Square | 2221048384 |
| Cube | 104673568241152 |
| Square root | 217.089843 (= 2√11782) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 83 |
| Scientific notation | 4.7128 × |
47128 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand one hundred and twenty-eight |
| Binary (base 2) | 1011100000011000 |
| Octal (base 8) | 134030 |
| Hexadecimal (base 16) | B818 |
| Base 3 | 2101122111 |
| As time | 47128 seconds = 13 h 5 min 28 s |
Is 47128 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (47128 ÷ 2 = 23564) | 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 (47128 ÷ 4 = 11782) | 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 4) | 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 (47128 ÷ 8 = 5891) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 4) | 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 47128 a prime number?
No. 47128 = × 43 × 137, so it is divisible by 2.
What are the factors of 47128?
1, 2, 4, 8, 43, 86, 137, 172, 274, 344, 548, 1096, 5891, 11782, 23564, 47128.
What is 47128 in binary?
1011100000011000 (hexadecimal B818, octal 134030).
What is the square root of 47128?
About 217.0898, exactly 2√11782.
Is 47128 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 47128?
It is a composite number with 16 divisors.