The number 31975
31975 is a composite number with 6 divisors. Its prime factorisation is Ć 1279. Divisors (6): 1, 5, 25, 1279, 6395, 31975.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31975: a Harshad number: divisible by its digit sum 25.
- 2
31975 is composite. Its prime factorisation is
- 3
The divisors add up to 39680; without 31975 itself that is 7705, so 31975 is deficient (7705 is less than 31975). Euler's totient Ļ(31975) = 25560 numbers up to 31975 share no factor with it.
- 4
The digits of 31975 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
\[ 31975 = 5^{2} \times 1279 \]31975 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 39680 |
| Euler totient Ļ(n) | 25560 |
| Square | 1022400625 |
| Cube | 32691259984375 |
| Square root | 178.815547 (= 5ā1279) |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 191 |
| Scientific notation | 3.1975 Ć |
31975 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and seventy-five |
| Binary (base 2) | 111110011100111 |
| Octal (base 8) | 76347 |
| Hexadecimal (base 16) | 7CE7 |
| Base 3 | 1121212021 |
| As time | 31975 seconds = 8 h 52 min 55 s |
Is 31975 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 | Yes (31975 Ć· 5 = 6395) | 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 7) | 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 5) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31975 a prime number?
No. 31975 = Ć 1279, so it is divisible by 5.
What are the factors of 31975?
1, 5, 25, 1279, 6395, 31975.
What is 31975 in binary?
111110011100111 (hexadecimal 7CE7, octal 76347).
What is the square root of 31975?
About 178.8155, exactly 5ā1279.
Is 31975 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 31975?
31975 is a Harshad number: divisible by its digit sum 25.