The number 42777
42777 is a composite number with 18 divisors. Its prime factorisation is × × 97. Divisors (18): 1, 3, 7, 9, 21, 49, 63, 97, 147, 291, 441, 679, 873, 2037, 4753, 6111 … 42777.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42777: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42777 is composite. Its prime factorisation is
- 3
The divisors add up to 72618; without 42777 itself that is 29841, so 42777 is deficient (29841 is less than 42777). Euler's totient φ(42777) = 24192 numbers up to 42777 share no factor with it.
- 4
The digits of 42777 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 106 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42777 = 3^{2} \times 7^{2} \times 97 \]42777 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 72618 |
| Euler totient φ(n) | 24192 |
| Square | 1829871729 |
| Cube | 78276422951433 |
| Square root | 206.826014 (= 21√97) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 106 |
| Scientific notation | 4.2777 × |
42777 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand seven hundred and seventy-seven |
| Binary (base 2) | 1010011100011001 |
| Octal (base 8) | 123431 |
| Hexadecimal (base 16) | A719 |
| Base 3 | 2011200100 |
| As time | 42777 seconds = 11 h 52 min 57 s |
Is 42777 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 (42777 ÷ 3 = 14259) | 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 | No (remainder 2) | 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 (42777 ÷ 7 = 6111) | 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 | Yes (42777 ÷ 9 = 4753) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 42777 a prime number?
No. 42777 = × × 97, so it is divisible by 3.
What are the factors of 42777?
1, 3, 7, 9, 21, 49, 63, 97, 147, 291, 441, 679, 873, 2037, 4753, 6111, 14259, 42777.
What is 42777 in binary?
1010011100011001 (hexadecimal A719, octal 123431).
What is the square root of 42777?
About 206.8260, exactly 21√97.
Is 42777 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 42777?
42777 is a happy number: repeatedly adding the squares of its digits reaches 1.