The number 31031
31031 is a composite number with 16 divisors. Its prime factorisation is 7 × 11 × 13 × 31. Divisors (16): 1, 7, 11, 13, 31, 77, 91, 143, 217, 341, 403, 1001, 2387, 2821, 4433, 31031.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31031 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31031 is composite. Its prime factorisation is
- 3
The divisors add up to 43008; without 31031 itself that is 11977, so 31031 is deficient (11977 is less than 31031). Euler's totient φ(31031) = 21600 numbers up to 31031 share no factor with it.
- 4
The digits of 31031 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31031 = 7 \times 11 \times 13 \times 31 \]
31031 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 43008 |
| Euler totient φ(n) | 21600 |
| Square | 962922961 |
| Cube | 29880462402791 |
| Square root | 176.156181 |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1031 × |
31031 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand and thirty-one |
| Binary (base 2) | 111100100110111 |
| Octal (base 8) | 74467 |
| Hexadecimal (base 16) | 7937 |
| Base 3 | 1120120022 |
| As time | 31031 seconds = 8 h 37 min 11 s |
Is 31031 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 (31031 ÷ 7 = 4433) | 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 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (31031 ÷ 11 = 2821) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31031 a prime number?
No. 31031 = 7 × 11 × 13 × 31, so it is divisible by 7.
What are the factors of 31031?
1, 7, 11, 13, 31, 77, 91, 143, 217, 341, 403, 1001, 2387, 2821, 4433, 31031.
What is 31031 in binary?
111100100110111 (hexadecimal 7937, octal 74467).
What is the square root of 31031?
About 176.1562.
Is 31031 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 31031?
It is a composite number with 16 divisors.