The number 57991
57991 is the 5873rd prime number. Its only divisors are 1 and 57991.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 57991: the 5873rd prime number.
- 2
57991 is prime, so its only factors are 1 and 57991. It is the 5873rd prime; the next prime is 58013 and the one before is 57977.
- 3
The divisors add up to 57992; without 57991 itself that is 1, so 57991 is deficient (1 is less than 57991). Euler's totient φ(57991) = 57990 numbers up to 57991 share no factor with it.
- 4
The digits of 57991 add up to 31, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 135 steps to reach 1.
57991 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 57992 |
| Euler totient φ(n) | 57990 |
| Square | 3362956081 |
| Cube | 195021186093271 |
| Square root | 240.813206 |
| Digit sum / digital root | 31 / 4 |
| Collatz steps to 1 | 135 |
| Scientific notation | 5.7991 × |
57991 in other forms
| Form | Value |
|---|---|
| In words | fifty-seven thousand nine hundred and ninety-one |
| Binary (base 2) | 1110001010000111 |
| Octal (base 8) | 161207 |
| Hexadecimal (base 16) | E287 |
| Base 3 | 2221112211 |
| As time | 57991 seconds = 16 h 6 min 31 s |
Is 57991 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 3) | 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 4) | 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 10) | 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 57991 a prime number?
Yes. 57991 is divisible only by 1 and itself.
What are the factors of 57991?
1, 57991.
What is 57991 in binary?
1110001010000111 (hexadecimal E287, octal 161207).
What is the square root of 57991?
About 240.8132.
Is 57991 divisible by 3?
No. Its digits add up to 31, which is not a multiple of 3.
What is special about the number 57991?
57991 is the 5873rd prime number.