The number 31091
31091 is the 3350th prime number. Its only divisors are 1 and 31091.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31091: the 3350th prime number.
- 2
31091 is prime, so its only factors are 1 and 31091. It is the 3350th prime; the next prime is 31121 and the one before is 31081.
- 3
The divisors add up to 31092; without 31091 itself that is 1, so 31091 is deficient (1 is less than 31091). Euler's totient φ(31091) = 31090 numbers up to 31091 share no factor with it.
- 4
The digits of 31091 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 116 steps to reach 1.
31091 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31092 |
| Euler totient φ(n) | 31090 |
| Square | 966650281 |
| Cube | 30054123886571 |
| Square root | 176.326402 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 116 |
| Scientific notation | 3.1091 × |
31091 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand and ninety-one |
| Binary (base 2) | 111100101110011 |
| Octal (base 8) | 74563 |
| Hexadecimal (base 16) | 7973 |
| Base 3 | 1120122112 |
| As time | 31091 seconds = 8 h 38 min 11 s |
Is 31091 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 1) | 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 5) | 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 31091 a prime number?
Yes. 31091 is divisible only by 1 and itself.
What are the factors of 31091?
1, 31091.
What is 31091 in binary?
111100101110011 (hexadecimal 7973, octal 74563).
What is the square root of 31091?
About 176.3264.
Is 31091 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 31091?
31091 is the 3350th prime number.