The number 78427
78427 is the 7696th prime number. Its only divisors are 1 and 78427.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 78427: the 7696th prime number.
- 2
78427 is prime, so its only factors are 1 and 78427. It is the 7696th prime; the next prime is 78437 and the one before is 78401.
- 3
The divisors add up to 78428; without 78427 itself that is 1, so 78427 is deficient (1 is less than 78427). Euler's totient φ(78427) = 78426 numbers up to 78427 share no factor with it.
- 4
The digits of 78427 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 81 steps to reach 1.
78427 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 78428 |
| Euler totient φ(n) | 78426 |
| Square | 6150794329 |
| Cube | 482388346840483 |
| Square root | 280.048210 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 81 |
| Scientific notation | 7.8427 × |
78427 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand four hundred and twenty-seven |
| Binary (base 2) | 10011001001011011 |
| Octal (base 8) | 231133 |
| Hexadecimal (base 16) | 1325B |
| Base 3 | 10222120201 |
| As time | 78427 seconds = 21 h 47 min 7 s |
Is 78427 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 | 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 6) | 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 3) | 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 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 78427 a prime number?
Yes. 78427 is divisible only by 1 and itself.
What are the factors of 78427?
1, 78427.
What is 78427 in binary?
10011001001011011 (hexadecimal 1325B, octal 231133).
What is the square root of 78427?
About 280.0482.
Is 78427 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 78427?
78427 is the 7696th prime number.