The number 42487
42487 is the 4445th prime number. Its only divisors are 1 and 42487.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42487: the 4445th prime number.
- 2
42487 is prime, so its only factors are 1 and 42487. It is the 4445th prime; the next prime is 42491 and the one before is 42473.
- 3
The divisors add up to 42488; without 42487 itself that is 1, so 42487 is deficient (1 is less than 42487). Euler's totient φ(42487) = 42486 numbers up to 42487 share no factor with it.
- 4
The digits of 42487 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 101 steps to reach 1.
42487 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 42488 |
| Euler totient φ(n) | 42486 |
| Square | 1805145169 |
| Cube | 76695202795303 |
| Square root | 206.123749 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 101 |
| Scientific notation | 4.2487 × |
42487 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand four hundred and eighty-seven |
| Binary (base 2) | 1010010111110111 |
| Octal (base 8) | 122767 |
| Hexadecimal (base 16) | A5F7 |
| Base 3 | 2011021121 |
| As time | 42487 seconds = 11 h 48 min 7 s |
Is 42487 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 1) | 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 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42487 a prime number?
Yes. 42487 is divisible only by 1 and itself.
What are the factors of 42487?
1, 42487.
What is 42487 in binary?
1010010111110111 (hexadecimal A5F7, octal 122767).
What is the square root of 42487?
About 206.1237.
Is 42487 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 42487?
42487 is the 4445th prime number.