The number 40391
40391 is a composite number with 6 divisors. Its prime factorisation is Ć 239. Divisors (6): 1, 13, 169, 239, 3107, 40391.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
40391 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
40391 is composite. Its prime factorisation is
- 3
The divisors add up to 43920; without 40391 itself that is 3529, so 40391 is deficient (3529 is less than 40391). Euler's totient Ļ(40391) = 37128 numbers up to 40391 share no factor with it.
- 4
The digits of 40391 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 137 steps to reach 1.
LaTeX source of the formulas on this page
\[ 40391 = 13^{2} \times 239 \]40391 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 43920 |
| Euler totient Ļ(n) | 37128 |
| Square | 1631432881 |
| Cube | 65895205496471 |
| Square root | 200.975123 (= 13ā239) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 137 |
| Scientific notation | 4.0391 Ć |
40391 in other forms
| Form | Value |
|---|---|
| In words | forty thousand three hundred and ninety-one |
| Binary (base 2) | 1001110111000111 |
| Octal (base 8) | 116707 |
| Hexadecimal (base 16) | 9DC7 |
| Base 3 | 2001101222 |
| As time | 40391 seconds = 11 h 13 min 11 s |
Is 40391 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 | 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 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 | No (remainder 10) | 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 40391 a prime number?
No. 40391 = Ć 239, so it is divisible by 13.
What are the factors of 40391?
1, 13, 169, 239, 3107, 40391.
What is 40391 in binary?
1001110111000111 (hexadecimal 9DC7, octal 116707).
What is the square root of 40391?
About 200.9751, exactly 13ā239.
Is 40391 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 40391?
It is a composite number with 6 divisors.