The number 31993
31993 is a composite number with 8 divisors. Its prime factorisation is 13 × 23 × 107. Divisors (8): 1, 13, 23, 107, 299, 1391, 2461, 31993.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31993 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31993 is composite. Its prime factorisation is
- 3
The divisors add up to 36288; without 31993 itself that is 4295, so 31993 is deficient (4295 is less than 31993). Euler's totient φ(31993) = 27984 numbers up to 31993 share no factor with it.
- 4
The digits of 31993 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 191 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31993 = 13 \times 23 \times 107 \]
31993 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 36288 |
| Euler totient φ(n) | 27984 |
| Square | 1023552049 |
| Cube | 32746500703657 |
| Square root | 178.865872 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 191 |
| Scientific notation | 3.1993 × |
31993 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and ninety-three |
| Binary (base 2) | 111110011111001 |
| Octal (base 8) | 76371 |
| Hexadecimal (base 16) | 7CF9 |
| Base 3 | 1121212221 |
| As time | 31993 seconds = 8 h 53 min 13 s |
Is 31993 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 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 3) | 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 1) | 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 5) | 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 31993 a prime number?
No. 31993 = 13 × 23 × 107, so it is divisible by 13.
What are the factors of 31993?
1, 13, 23, 107, 299, 1391, 2461, 31993.
What is 31993 in binary?
111110011111001 (hexadecimal 7CF9, octal 76371).
What is the square root of 31993?
About 178.8659.
Is 31993 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 31993?
It is a composite number with 8 divisors.