The number 42839
42839 is a twin prime (42839 and 42841 are both prime) and the 4479th prime number. Its only divisors are 1 and 42839.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42839: a twin prime (42839 and 42841 are both prime); the 4479th prime number.
- 2
42839 is prime, so its only factors are 1 and 42839. It is the 4479th prime; the next prime is 42841 and the one before is 42829.
- 3
The divisors add up to 42840; without 42839 itself that is 1, so 42839 is deficient (1 is less than 42839). Euler's totient φ(42839) = 42838 numbers up to 42839 share no factor with it.
- 4
The digits of 42839 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 101 steps to reach 1.
42839 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 42840 |
| Euler totient φ(n) | 42838 |
| Square | 1835179921 |
| Cube | 78617272635719 |
| Square root | 206.975844 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 101 |
| Scientific notation | 4.2839 × |
42839 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand eight hundred and thirty-nine |
| Binary (base 2) | 1010011101010111 |
| Octal (base 8) | 123527 |
| Hexadecimal (base 16) | A757 |
| Base 3 | 2011202122 |
| As time | 42839 seconds = 11 h 53 min 59 s |
Is 42839 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 2) | 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 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42839 a prime number?
Yes. 42839 is divisible only by 1 and itself.
What are the factors of 42839?
1, 42839.
What is 42839 in binary?
1010011101010111 (hexadecimal A757, octal 123527).
What is the square root of 42839?
About 206.9758.
Is 42839 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 42839?
42839 is a twin prime (42839 and 42841 are both prime); the 4479th prime number.