The number 31957
31957 is the 3428th prime number. Its only divisors are 1 and 31957.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31957: the 3428th prime number.
- 2
31957 is prime, so its only factors are 1 and 31957. It is the 3428th prime; the next prime is 31963 and the one before is 31907.
- 3
The divisors add up to 31958; without 31957 itself that is 1, so 31957 is deficient (1 is less than 31957). Euler's totient φ(31957) = 31956 numbers up to 31957 share no factor with it.
- 4
The digits of 31957 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
31957 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31958 |
| Euler totient φ(n) | 31956 |
| Square | 1021249849 |
| Cube | 32636081424493 |
| Square root | 178.765209 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1957 × |
31957 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and fifty-seven |
| Binary (base 2) | 111110011010101 |
| Octal (base 8) | 76325 |
| Hexadecimal (base 16) | 7CD5 |
| Base 3 | 1121211121 |
| As time | 31957 seconds = 8 h 52 min 37 s |
Is 31957 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | 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 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 5) | 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 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31957 a prime number?
Yes. 31957 is divisible only by 1 and itself.
What are the factors of 31957?
1, 31957.
What is 31957 in binary?
111110011010101 (hexadecimal 7CD5, octal 76325).
What is the square root of 31957?
About 178.7652.
Is 31957 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 31957?
31957 is the 3428th prime number.