The number 20771
20771 is a twin prime (20771 and 20773 are both prime) and the 2340th prime number. Its only divisors are 1 and 20771.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20771: a twin prime (20771 and 20773 are both prime); the 2340th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
20771 is prime, so its only factors are 1 and 20771. It is the 2340th prime; the next prime is 20773 and the one before is 20759.
- 3
The divisors add up to 20772; without 20771 itself that is 1, so 20771 is deficient (1 is less than 20771). Euler's totient φ(20771) = 20770 numbers up to 20771 share no factor with it.
- 4
The digits of 20771 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 87 steps to reach 1.
20771 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 20772 |
| Euler totient φ(n) | 20770 |
| Square | 431434441 |
| Cube | 8961324774011 |
| Square root | 144.121477 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.0771 × |
20771 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and seventy-one |
| Binary (base 2) | 101000100100011 |
| Octal (base 8) | 50443 |
| Hexadecimal (base 16) | 5123 |
| Base 3 | 1001111022 |
| As time | 20771 seconds = 5 h 46 min 11 s |
Is 20771 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 2) | 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 8) | 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 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20771 a prime number?
Yes. 20771 is divisible only by 1 and itself.
What are the factors of 20771?
1, 20771.
What is 20771 in binary?
101000100100011 (hexadecimal 5123, octal 50443).
What is the square root of 20771?
About 144.1215.
Is 20771 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 20771?
20771 is a twin prime (20771 and 20773 are both prime); the 2340th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.