The number 31109
31109 is a composite number with 4 divisors. Its prime factorisation is 13 × 2393. Divisors (4): 1, 13, 2393, 31109.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31109: a semiprime: 13 × 2393, the product of two primes.
- 2
31109 is composite. Its prime factorisation is
- 3
The divisors add up to 33516; without 31109 itself that is 2407, so 31109 is deficient (2407 is less than 31109). Euler's totient φ(31109) = 28704 numbers up to 31109 share no factor with it.
- 4
The digits of 31109 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31109 = 13 \times 2393 \]
31109 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 33516 |
| Euler totient φ(n) | 28704 |
| Square | 967769881 |
| Cube | 30106353228029 |
| Square root | 176.377436 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1109 × |
31109 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand one hundred and nine |
| Binary (base 2) | 111100110000101 |
| Octal (base 8) | 74605 |
| Hexadecimal (base 16) | 7985 |
| Base 3 | 1120200012 |
| As time | 31109 seconds = 8 h 38 min 29 s |
Is 31109 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 4) | 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 | No (remainder 1) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 31109 a prime number?
No. 31109 = 13 × 2393, so it is divisible by 13.
What are the factors of 31109?
1, 13, 2393, 31109.
What is 31109 in binary?
111100110000101 (hexadecimal 7985, octal 74605).
What is the square root of 31109?
About 176.3774.
Is 31109 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 31109?
31109 is a semiprime: 13 × 2393, the product of two primes.