The number 87831
87831 is a composite number with 8 divisors. Its prime factorisation is × 3253. Divisors (8): 1, 3, 9, 27, 3253, 9759, 29277, 87831.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87831: a Harshad number: divisible by its digit sum 27.
- 2
87831 is composite. Its prime factorisation is
- 3
The divisors add up to 130160; without 87831 itself that is 42329, so 87831 is deficient (42329 is less than 87831). Euler's totient φ(87831) = 58536 numbers up to 87831 share no factor with it.
- 4
The digits of 87831 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 151 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87831 = 3^{3} \times 3253 \]87831 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 130160 |
| Euler totient φ(n) | 58536 |
| Square | 7714284561 |
| Cube | 677553327277191 |
| Square root | 296.362953 (= 3√9759) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 151 |
| Scientific notation | 8.7831 × |
87831 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand eight hundred and thirty-one |
| Binary (base 2) | 10101011100010111 |
| Octal (base 8) | 253427 |
| Hexadecimal (base 16) | 15717 |
| Base 3 | 11110111000 |
| As time | 87831 seconds = 24 h 23 min 51 s |
Is 87831 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (87831 ÷ 3 = 29277) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 3) | 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 | No (remainder 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (87831 ÷ 9 = 9759) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87831 a prime number?
No. 87831 = × 3253, so it is divisible by 3.
What are the factors of 87831?
1, 3, 9, 27, 3253, 9759, 29277, 87831.
What is 87831 in binary?
10101011100010111 (hexadecimal 15717, octal 253427).
What is the square root of 87831?
About 296.3630, exactly 3√9759.
Is 87831 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 87831?
87831 is a Harshad number: divisible by its digit sum 27.