The number 775
775 is a composite number with 6 divisors. Its prime factorisation is Ć 31. Divisors (6): 1, 5, 25, 31, 155, 775.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
775 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
775 is composite. Its prime factorisation is
- 3
The divisors add up to 992; without 775 itself that is 217, so 775 is deficient (217 is less than 775). Euler's totient Ļ(775) = 600 numbers up to 775 share no factor with it.
- 4
The digits of 775 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 152 steps to reach 1.
LaTeX source of the formulas on this page
\[ 775 = 5^{2} \times 31 \]775 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 992 |
| Euler totient Ļ(n) | 600 |
| Square | 600625 |
| Cube | 465484375 |
| Square root | 27.838822 (= 5ā31) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 152 |
| Scientific notation | 7.75 Ć |
775 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and seventy-five |
| Roman numerals | DCCLXXV |
| Binary (base 2) | 1100000111 |
| Octal (base 8) | 1407 |
| Hexadecimal (base 16) | 307 |
| Base 3 | 1001201 |
| As time | 775 seconds = 12 min 55 s |
Is 775 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 1) | 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 | Yes (775 Ć· 5 = 155) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 1) | 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 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 775 a prime number?
No. 775 = Ć 31, so it is divisible by 5.
What are the factors of 775?
1, 5, 25, 31, 155, 775.
What is 775 in binary?
1100000111 (hexadecimal 307, octal 1407).
What is the square root of 775?
About 27.8388, exactly 5ā31.
What is 775 in Roman numerals?
DCCLXXV.
Is 775 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 775?
It is a composite number with 6 divisors.