The number 77391
77391 is a composite number with 6 divisors. Its prime factorisation is × 8599. Divisors (6): 1, 3, 9, 8599, 25797, 77391.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
77391 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
77391 is composite. Its prime factorisation is
- 3
The divisors add up to 111800; without 77391 itself that is 34409, so 77391 is deficient (34409 is less than 77391). Euler's totient φ(77391) = 51588 numbers up to 77391 share no factor with it.
- 4
The digits of 77391 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77391 = 3^{2} \times 8599 \]77391 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 111800 |
| Euler totient φ(n) | 51588 |
| Square | 5989366881 |
| Cube | 463523092287471 |
| Square root | 278.192379 (= 3√8599) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 138 |
| Scientific notation | 7.7391 × |
77391 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand three hundred and ninety-one |
| Binary (base 2) | 10010111001001111 |
| Octal (base 8) | 227117 |
| Hexadecimal (base 16) | 12E4F |
| Base 3 | 10221011100 |
| As time | 77391 seconds = 21 h 29 min 51 s |
Is 77391 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 | Yes (77391 ÷ 3 = 25797) | 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 3) | 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 | Yes (77391 ÷ 9 = 8599) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77391 a prime number?
No. 77391 = × 8599, so it is divisible by 3.
What are the factors of 77391?
1, 3, 9, 8599, 25797, 77391.
What is 77391 in binary?
10010111001001111 (hexadecimal 12E4F, octal 227117).
What is the square root of 77391?
About 278.1924, exactly 3√8599.
Is 77391 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 77391?
It is a composite number with 6 divisors.