The number 77775
77775 is a composite number with 24 divisors. Its prime factorisation is 3 × × 17 × 61. Divisors (24): 1, 3, 5, 15, 17, 25, 51, 61, 75, 85, 183, 255, 305, 425, 915, 1037 … 77775.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
77775 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
77775 is composite. Its prime factorisation is
- 3
The divisors add up to 138384; without 77775 itself that is 60609, so 77775 is deficient (60609 is less than 77775). Euler's totient φ(77775) = 38400 numbers up to 77775 share no factor with it.
- 4
The digits of 77775 add up to 33, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77775 = 3 \times 5^{2} \times 17 \times 61 \]77775 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 138384 |
| Euler totient φ(n) | 38400 |
| Square | 6048950625 |
| Cube | 470457134859375 |
| Square root | 278.881695 (= 5√3111) |
| Digit sum / digital root | 33 / 6 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.7775 × |
77775 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand seven hundred and seventy-five |
| Binary (base 2) | 10010111111001111 |
| Octal (base 8) | 227717 |
| Hexadecimal (base 16) | 12FCF |
| Base 3 | 10221200120 |
| As time | 77775 seconds = 21 h 36 min 15 s |
Is 77775 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 (77775 ÷ 3 = 25925) | 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 (77775 ÷ 5 = 15555) | 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 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 6) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77775 a prime number?
No. 77775 = 3 × × 17 × 61, so it is divisible by 3.
What are the factors of 77775?
1, 3, 5, 15, 17, 25, 51, 61, 75, 85, 183, 255, 305, 425, 915, 1037, 1275, 1525, 3111, 4575, 5185, 15555, 25925, 77775.
What is 77775 in binary?
10010111111001111 (hexadecimal 12FCF, octal 227717).
What is the square root of 77775?
About 278.8817, exactly 5√3111.
Is 77775 divisible by 3?
Yes. Its digits add up to 33, a multiple of 3.
What is special about the number 77775?
It is a composite number with 24 divisors.