The number 87291
87291 is a composite number with 16 divisors. Its prime factorisation is × 53 × 61. Divisors (16): 1, 3, 9, 27, 53, 61, 159, 183, 477, 549, 1431, 1647, 3233, 9699, 29097, 87291.
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How to work it out
- 1
What is special about 87291: a Harshad number: divisible by its digit sum 27.
- 2
87291 is composite. Its prime factorisation is
- 3
The divisors add up to 133920; without 87291 itself that is 46629, so 87291 is deficient (46629 is less than 87291). Euler's totient φ(87291) = 56160 numbers up to 87291 share no factor with it.
- 4
The digits of 87291 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 133 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87291 = 3^{3} \times 53 \times 61 \]87291 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 133920 |
| Euler totient φ(n) | 56160 |
| Square | 7619718681 |
| Cube | 665132863383171 |
| Square root | 295.450503 (= 3√9699) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 133 |
| Scientific notation | 8.7291 × |
87291 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand two hundred and ninety-one |
| Binary (base 2) | 10101010011111011 |
| Octal (base 8) | 252373 |
| Hexadecimal (base 16) | 154FB |
| Base 3 | 11102202000 |
| As time | 87291 seconds = 24 h 14 min 51 s |
Is 87291 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 (87291 ÷ 3 = 29097) | 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 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 | No (remainder 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (87291 ÷ 9 = 9699) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87291 a prime number?
No. 87291 = × 53 × 61, so it is divisible by 3.
What are the factors of 87291?
1, 3, 9, 27, 53, 61, 159, 183, 477, 549, 1431, 1647, 3233, 9699, 29097, 87291.
What is 87291 in binary?
10101010011111011 (hexadecimal 154FB, octal 252373).
What is the square root of 87291?
About 295.4505, exactly 3√9699.
Is 87291 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 87291?
87291 is a Harshad number: divisible by its digit sum 27.