The number 31247
31247 is a twin prime (31247 and 31249 are both prime) and the 3367th prime number. Its only divisors are 1 and 31247.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31247: a twin prime (31247 and 31249 are both prime); the 3367th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
31247 is prime, so its only factors are 1 and 31247. It is the 3367th prime; the next prime is 31249 and the one before is 31237.
- 3
The divisors add up to 31248; without 31247 itself that is 1, so 31247 is deficient (1 is less than 31247). Euler's totient φ(31247) = 31246 numbers up to 31247 share no factor with it.
- 4
The digits of 31247 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 253 steps to reach 1.
31247 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31248 |
| Euler totient φ(n) | 31246 |
| Square | 976375009 |
| Cube | 30508789906223 |
| Square root | 176.768210 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 253 |
| Scientific notation | 3.1247 × |
31247 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand two hundred and forty-seven |
| Binary (base 2) | 111101000001111 |
| Octal (base 8) | 75017 |
| Hexadecimal (base 16) | 7A0F |
| Base 3 | 1120212022 |
| As time | 31247 seconds = 8 h 40 min 47 s |
Is 31247 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 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 8) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31247 a prime number?
Yes. 31247 is divisible only by 1 and itself.
What are the factors of 31247?
1, 31247.
What is 31247 in binary?
111101000001111 (hexadecimal 7A0F, octal 75017).
What is the square root of 31247?
About 176.7682.
Is 31247 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 31247?
31247 is a twin prime (31247 and 31249 are both prime); the 3367th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.