The number 87321
87321 is a composite number with 8 divisors. Its prime factorisation is 3 × 13 × 2239. Divisors (8): 1, 3, 13, 39, 2239, 6717, 29107, 87321.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
87321 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
87321 is composite. Its prime factorisation is
- 3
The divisors add up to 125440; without 87321 itself that is 38119, so 87321 is deficient (38119 is less than 87321). Euler's totient φ(87321) = 53712 numbers up to 87321 share no factor with it.
- 4
The digits of 87321 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 195 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87321 = 3 \times 13 \times 2239 \]
87321 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 125440 |
| Euler totient φ(n) | 53712 |
| Square | 7624957041 |
| Cube | 665818873777161 |
| Square root | 295.501269 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 195 |
| Scientific notation | 8.7321 × |
87321 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand three hundred and twenty-one |
| Binary (base 2) | 10101010100011001 |
| Octal (base 8) | 252431 |
| Hexadecimal (base 16) | 15519 |
| Base 3 | 11102210010 |
| As time | 87321 seconds = 24 h 15 min 21 s |
Is 87321 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 (87321 ÷ 3 = 29107) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | 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 3) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87321 a prime number?
No. 87321 = 3 × 13 × 2239, so it is divisible by 3.
What are the factors of 87321?
1, 3, 13, 39, 2239, 6717, 29107, 87321.
What is 87321 in binary?
10101010100011001 (hexadecimal 15519, octal 252431).
What is the square root of 87321?
About 295.5013.
Is 87321 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 87321?
It is a composite number with 8 divisors.