The number 72775
72775 is a composite number with 12 divisors. Its prime factorisation is × 41 × 71. Divisors (12): 1, 5, 25, 41, 71, 205, 355, 1025, 1775, 2911, 14555, 72775.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72775: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
72775 is composite. Its prime factorisation is
- 3
The divisors add up to 93744; without 72775 itself that is 20969, so 72775 is deficient (20969 is less than 72775). Euler's totient φ(72775) = 56000 numbers up to 72775 share no factor with it.
- 4
The digits of 72775 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 187 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72775 = 5^{2} \times 41 \times 71 \]72775 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 93744 |
| Euler totient φ(n) | 56000 |
| Square | 5296200625 |
| Cube | 385431000484375 |
| Square root | 269.768419 (= 5√2911) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.2775 × |
72775 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand seven hundred and seventy-five |
| Binary (base 2) | 10001110001000111 |
| Octal (base 8) | 216107 |
| Hexadecimal (base 16) | 11C47 |
| Base 3 | 10200211101 |
| As time | 72775 seconds = 20 h 12 min 55 s |
Is 72775 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 (72775 ÷ 5 = 14555) | 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 3) | 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 10) | 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 72775 a prime number?
No. 72775 = × 41 × 71, so it is divisible by 5.
What are the factors of 72775?
1, 5, 25, 41, 71, 205, 355, 1025, 1775, 2911, 14555, 72775.
What is 72775 in binary?
10001110001000111 (hexadecimal 11C47, octal 216107).
What is the square root of 72775?
About 269.7684, exactly 5√2911.
Is 72775 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 72775?
72775 is a happy number: repeatedly adding the squares of its digits reaches 1.