The number 31771
31771 is a twin prime (31769 and 31771 are both prime) and the 3417th prime number. Its only divisors are 1 and 31771.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31771: a twin prime (31769 and 31771 are both prime); the 3417th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
31771 is prime, so its only factors are 1 and 31771. It is the 3417th prime; the next prime is 31793 and the one before is 31769.
- 3
The divisors add up to 31772; without 31771 itself that is 1, so 31771 is deficient (1 is less than 31771). Euler's totient φ(31771) = 31770 numbers up to 31771 share no factor with it.
- 4
The digits of 31771 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 129 steps to reach 1.
31771 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31772 |
| Euler totient φ(n) | 31770 |
| Square | 1009396441 |
| Cube | 32069534327011 |
| Square root | 178.244214 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 129 |
| Scientific notation | 3.1771 × |
31771 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand seven hundred and seventy-one |
| Binary (base 2) | 111110000011011 |
| Octal (base 8) | 76033 |
| Hexadecimal (base 16) | 7C1B |
| Base 3 | 1121120201 |
| As time | 31771 seconds = 8 h 49 min 31 s |
Is 31771 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 5) | 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 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 3) | 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 31771 a prime number?
Yes. 31771 is divisible only by 1 and itself.
What are the factors of 31771?
1, 31771.
What is 31771 in binary?
111110000011011 (hexadecimal 7C1B, octal 76033).
What is the square root of 31771?
About 178.2442.
Is 31771 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 31771?
31771 is a twin prime (31769 and 31771 are both prime); the 3417th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.