The number 31723
31723 is a twin prime (31721 and 31723 are both prime) and the 3411th prime number. Its only divisors are 1 and 31723.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31723: a twin prime (31721 and 31723 are both prime); the 3411th prime number.
- 2
31723 is prime, so its only factors are 1 and 31723. It is the 3411th prime; the next prime is 31727 and the one before is 31721.
- 3
The divisors add up to 31724; without 31723 itself that is 1, so 31723 is deficient (1 is less than 31723). Euler's totient φ(31723) = 31722 numbers up to 31723 share no factor with it.
- 4
The digits of 31723 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
31723 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31724 |
| Euler totient φ(n) | 31722 |
| Square | 1006348729 |
| Cube | 31924400730067 |
| Square root | 178.109517 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 103 |
| Scientific notation | 3.1723 × |
31723 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand seven hundred and twenty-three |
| Binary (base 2) | 111101111101011 |
| Octal (base 8) | 75753 |
| Hexadecimal (base 16) | 7BEB |
| Base 3 | 1121111221 |
| As time | 31723 seconds = 8 h 48 min 43 s |
Is 31723 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 3) | 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 6) | 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 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | 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 31723 a prime number?
Yes. 31723 is divisible only by 1 and itself.
What are the factors of 31723?
1, 31723.
What is 31723 in binary?
111101111101011 (hexadecimal 7BEB, octal 75753).
What is the square root of 31723?
About 178.1095.
Is 31723 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 31723?
31723 is a twin prime (31721 and 31723 are both prime); the 3411th prime number.