The number 31231
31231 is the 3365th prime number. Its only divisors are 1 and 31231.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31231: the 3365th prime number.
- 2
31231 is prime, so its only factors are 1 and 31231. It is the 3365th prime; the next prime is 31237 and the one before is 31223.
- 3
The divisors add up to 31232; without 31231 itself that is 1, so 31231 is deficient (1 is less than 31231). Euler's totient φ(31231) = 31230 numbers up to 31231 share no factor with it.
- 4
The digits of 31231 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 253 steps to reach 1.
31231 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31232 |
| Euler totient φ(n) | 31230 |
| Square | 975375361 |
| Cube | 30461947899391 |
| Square root | 176.722947 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 253 |
| Scientific notation | 3.1231 × |
31231 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand two hundred and thirty-one |
| Binary (base 2) | 111100111111111 |
| Octal (base 8) | 74777 |
| Hexadecimal (base 16) | 79FF |
| Base 3 | 1120211201 |
| As time | 31231 seconds = 8 h 40 min 31 s |
Is 31231 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 1) | 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 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 31231 a prime number?
Yes. 31231 is divisible only by 1 and itself.
What are the factors of 31231?
1, 31231.
What is 31231 in binary?
111100111111111 (hexadecimal 79FF, octal 74777).
What is the square root of 31231?
About 176.7229.
Is 31231 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 31231?
31231 is the 3365th prime number.