The number 77385
77385 is a composite number with 32 divisors. Its prime factorisation is 3 × 5 × 7 × 11 × 67. Divisors (32): 1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 67, 77, 105, 165, 201, 231 … 77385.
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How to work it out
- 1
77385 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
77385 is composite. Its prime factorisation is
- 3
The divisors add up to 156672; without 77385 itself that is 79287, so 77385 is abundant (79287 is more than 77385). Euler's totient φ(77385) = 31680 numbers up to 77385 share no factor with it.
- 4
The digits of 77385 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77385 = 3 \times 5 \times 7 \times 11 \times 67 \]
77385 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 156672 |
| Euler totient φ(n) | 31680 |
| Square | 5988438225 |
| Cube | 463415292041625 |
| Square root | 278.181595 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 76 |
| Scientific notation | 7.7385 × |
77385 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand three hundred and eighty-five |
| Binary (base 2) | 10010111001001001 |
| Octal (base 8) | 227111 |
| Hexadecimal (base 16) | 12E49 |
| Base 3 | 10221011010 |
| As time | 77385 seconds = 21 h 29 min 45 s |
Is 77385 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 (77385 ÷ 3 = 25795) | 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 | Yes (77385 ÷ 5 = 15477) | 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 | Yes (77385 ÷ 7 = 11055) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 | Yes (77385 ÷ 11 = 7035) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77385 a prime number?
No. 77385 = 3 × 5 × 7 × 11 × 67, so it is divisible by 3.
What are the factors of 77385?
1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 67, 77, 105, 165, 201, 231, 335, 385, 469, 737, 1005, 1155, 1407, 2211, 2345, 3685, 5159, 7035, 11055, 15477, 25795, 77385.
What is 77385 in binary?
10010111001001001 (hexadecimal 12E49, octal 227111).
What is the square root of 77385?
About 278.1816.
Is 77385 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 77385?
It is a composite number with 32 divisors.