The number 42509
42509 is the 4448th prime number. Its only divisors are 1 and 42509.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42509: the 4448th prime number.
- 2
42509 is prime, so its only factors are 1 and 42509. It is the 4448th prime; the next prime is 42533 and the one before is 42499.
- 3
The divisors add up to 42510; without 42509 itself that is 1, so 42509 is deficient (1 is less than 42509). Euler's totient φ(42509) = 42508 numbers up to 42509 share no factor with it.
- 4
The digits of 42509 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
42509 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 42510 |
| Euler totient φ(n) | 42508 |
| Square | 1807015081 |
| Cube | 76814404078229 |
| Square root | 206.177108 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 57 |
| Scientific notation | 4.2509 × |
42509 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand five hundred and nine |
| Binary (base 2) | 1010011000001101 |
| Octal (base 8) | 123015 |
| Hexadecimal (base 16) | A60D |
| Base 3 | 2011022102 |
| As time | 42509 seconds = 11 h 48 min 29 s |
Is 42509 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 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 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 5) | 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 42509 a prime number?
Yes. 42509 is divisible only by 1 and itself.
What are the factors of 42509?
1, 42509.
What is 42509 in binary?
1010011000001101 (hexadecimal A60D, octal 123015).
What is the square root of 42509?
About 206.1771.
Is 42509 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 42509?
42509 is the 4448th prime number.