The number 31997
31997 is a composite number with 6 divisors. Its prime factorisation is Ć 653. Divisors (6): 1, 7, 49, 653, 4571, 31997.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31997 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31997 is composite. Its prime factorisation is
- 3
The divisors add up to 37278; without 31997 itself that is 5281, so 31997 is deficient (5281 is less than 31997). Euler's totient Ļ(31997) = 27384 numbers up to 31997 share no factor with it.
- 4
The digits of 31997 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 191 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31997 = 7^{2} \times 653 \]31997 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 37278 |
| Euler totient Ļ(n) | 27384 |
| Square | 1023808009 |
| Cube | 32758784863973 |
| Square root | 178.877053 (= 7ā653) |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 191 |
| Scientific notation | 3.1997 Ć |
31997 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and ninety-seven |
| Binary (base 2) | 111110011111101 |
| Octal (base 8) | 76375 |
| Hexadecimal (base 16) | 7CFD |
| Base 3 | 1121220002 |
| As time | 31997 seconds = 8 h 53 min 17 s |
Is 31997 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 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (31997 Ć· 7 = 4571) | 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 2) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31997 a prime number?
No. 31997 = Ć 653, so it is divisible by 7.
What are the factors of 31997?
1, 7, 49, 653, 4571, 31997.
What is 31997 in binary?
111110011111101 (hexadecimal 7CFD, octal 76375).
What is the square root of 31997?
About 178.8771, exactly 7ā653.
Is 31997 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 31997?
It is a composite number with 6 divisors.