The number 87731
87731 is a composite number with 8 divisors. Its prime factorisation is 7 × 83 × 151. Divisors (8): 1, 7, 83, 151, 581, 1057, 12533, 87731.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
87731 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
87731 is composite. Its prime factorisation is
- 3
The divisors add up to 102144; without 87731 itself that is 14413, so 87731 is deficient (14413 is less than 87731). Euler's totient φ(87731) = 73800 numbers up to 87731 share no factor with it.
- 4
The digits of 87731 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 120 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87731 = 7 \times 83 \times 151 \]
87731 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 102144 |
| Euler totient φ(n) | 73800 |
| Square | 7696728361 |
| Cube | 675241675838891 |
| Square root | 296.194193 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 120 |
| Scientific notation | 8.7731 × |
87731 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand seven hundred and thirty-one |
| Binary (base 2) | 10101011010110011 |
| Octal (base 8) | 253263 |
| Hexadecimal (base 16) | 156B3 |
| Base 3 | 11110100022 |
| As time | 87731 seconds = 24 h 22 min 11 s |
Is 87731 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 | No (remainder 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (87731 ÷ 7 = 12533) | 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 3) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87731 a prime number?
No. 87731 = 7 × 83 × 151, so it is divisible by 7.
What are the factors of 87731?
1, 7, 83, 151, 581, 1057, 12533, 87731.
What is 87731 in binary?
10101011010110011 (hexadecimal 156B3, octal 253263).
What is the square root of 87731?
About 296.1942.
Is 87731 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 87731?
It is a composite number with 8 divisors.