The number 77857
77857 is a composite number with 8 divisors. Its prime factorisation is 13 × 53 × 113. Divisors (8): 1, 13, 53, 113, 689, 1469, 5989, 77857.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77857: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
77857 is composite. Its prime factorisation is
- 3
The divisors add up to 86184; without 77857 itself that is 8327, so 77857 is deficient (8327 is less than 77857). Euler's totient φ(77857) = 69888 numbers up to 77857 share no factor with it.
- 4
The digits of 77857 add up to 34, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77857 = 13 \times 53 \times 113 \]
77857 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 86184 |
| Euler totient φ(n) | 69888 |
| Square | 6061712449 |
| Cube | 471946746141793 |
| Square root | 279.028672 |
| Digit sum / digital root | 34 / 7 |
| Collatz steps to 1 | 169 |
| Scientific notation | 7.7857 × |
77857 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand eight hundred and fifty-seven |
| Binary (base 2) | 10011000000100001 |
| Octal (base 8) | 230041 |
| Hexadecimal (base 16) | 13021 |
| Base 3 | 10221210121 |
| As time | 77857 seconds = 21 h 37 min 37 s |
Is 77857 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 | No (remainder 2) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 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 77857 a prime number?
No. 77857 = 13 × 53 × 113, so it is divisible by 13.
What are the factors of 77857?
1, 13, 53, 113, 689, 1469, 5989, 77857.
What is 77857 in binary?
10011000000100001 (hexadecimal 13021, octal 230041).
What is the square root of 77857?
About 279.0287.
Is 77857 divisible by 3?
No. Its digits add up to 34, which is not a multiple of 3.
What is special about the number 77857?
77857 is a happy number: repeatedly adding the squares of its digits reaches 1.