The number 87509
87509 is a twin prime (87509 and 87511 are both prime) and the 8493rd prime number. Its only divisors are 1 and 87509.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87509: a twin prime (87509 and 87511 are both prime); the 8493rd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
87509 is prime, so its only factors are 1 and 87509. It is the 8493rd prime; the next prime is 87511 and the one before is 87491.
- 3
The divisors add up to 87510; without 87509 itself that is 1, so 87509 is deficient (1 is less than 87509). Euler's totient φ(87509) = 87508 numbers up to 87509 share no factor with it.
- 4
The digits of 87509 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 45 steps to reach 1.
87509 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 87510 |
| Euler totient φ(n) | 87508 |
| Square | 7657825081 |
| Cube | 670128615013229 |
| Square root | 295.819202 |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 45 |
| Scientific notation | 8.7509 × |
87509 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand five hundred and nine |
| Binary (base 2) | 10101010111010101 |
| Octal (base 8) | 252725 |
| Hexadecimal (base 16) | 155D5 |
| Base 3 | 11110001002 |
| As time | 87509 seconds = 24 h 18 min 29 s |
Is 87509 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87509 a prime number?
Yes. 87509 is divisible only by 1 and itself.
What are the factors of 87509?
1, 87509.
What is 87509 in binary?
10101010111010101 (hexadecimal 155D5, octal 252725).
What is the square root of 87509?
About 295.8192.
Is 87509 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 87509?
87509 is a twin prime (87509 and 87511 are both prime); the 8493rd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.