The number 77725
77725 is a composite number with 6 divisors. Its prime factorisation is Ć 3109. Divisors (6): 1, 5, 25, 3109, 15545, 77725.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77725: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
77725 is composite. Its prime factorisation is
- 3
The divisors add up to 96410; without 77725 itself that is 18685, so 77725 is deficient (18685 is less than 77725). Euler's totient Ļ(77725) = 62160 numbers up to 77725 share no factor with it.
- 4
The digits of 77725 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 125 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77725 = 5^{2} \times 3109 \]77725 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 96410 |
| Euler totient Ļ(n) | 62160 |
| Square | 6041175625 |
| Cube | 469550375453125 |
| Square root | 278.792037 (= 5ā3109) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 125 |
| Scientific notation | 7.7725 Ć |
77725 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand seven hundred and twenty-five |
| Binary (base 2) | 10010111110011101 |
| Octal (base 8) | 227635 |
| Hexadecimal (base 16) | 12F9D |
| Base 3 | 10221121201 |
| As time | 77725 seconds = 21 h 35 min 25 s |
Is 77725 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (77725 Ć· 5 = 15545) | 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 4) | 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 5) | 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 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77725 a prime number?
No. 77725 = Ć 3109, so it is divisible by 5.
What are the factors of 77725?
1, 5, 25, 3109, 15545, 77725.
What is 77725 in binary?
10010111110011101 (hexadecimal 12F9D, octal 227635).
What is the square root of 77725?
About 278.7920, exactly 5ā3109.
Is 77725 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 77725?
77725 is a happy number: repeatedly adding the squares of its digits reaches 1.