The number 87015
87015 is a composite number with 8 divisors. Its prime factorisation is 3 × 5 × 5801. Divisors (8): 1, 3, 5, 15, 5801, 17403, 29005, 87015.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87015: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
87015 is composite. Its prime factorisation is
- 3
The divisors add up to 139248; without 87015 itself that is 52233, so 87015 is deficient (52233 is less than 87015). Euler's totient φ(87015) = 46400 numbers up to 87015 share no factor with it.
- 4
The digits of 87015 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 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87015 = 3 \times 5 \times 5801 \]
87015 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 139248 |
| Euler totient φ(n) | 46400 |
| Square | 7571610225 |
| Cube | 658843663728375 |
| Square root | 294.983050 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 76 |
| Scientific notation | 8.7015 × |
87015 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand and fifteen |
| Binary (base 2) | 10101001111100111 |
| Octal (base 8) | 251747 |
| Hexadecimal (base 16) | 153E7 |
| Base 3 | 11102100210 |
| As time | 87015 seconds = 24 h 10 min 15 s |
Is 87015 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 (87015 ÷ 3 = 29005) | 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 | Yes (87015 ÷ 5 = 17403) | 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 5) | 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 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | 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 87015 a prime number?
No. 87015 = 3 × 5 × 5801, so it is divisible by 3.
What are the factors of 87015?
1, 3, 5, 15, 5801, 17403, 29005, 87015.
What is 87015 in binary?
10101001111100111 (hexadecimal 153E7, octal 251747).
What is the square root of 87015?
About 294.9831.
Is 87015 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 87015?
87015 is a happy number: repeatedly adding the squares of its digits reaches 1.