The number 42643
42643 is a twin prime (42641 and 42643 are both prime) and the 4457th prime number. Its only divisors are 1 and 42643.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42643: a twin prime (42641 and 42643 are both prime); the 4457th prime number.
- 2
42643 is prime, so its only factors are 1 and 42643. It is the 4457th prime; the next prime is 42649 and the one before is 42641.
- 3
The divisors add up to 42644; without 42643 itself that is 1, so 42643 is deficient (1 is less than 42643). Euler's totient φ(42643) = 42642 numbers up to 42643 share no factor with it.
- 4
The digits of 42643 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
42643 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 42644 |
| Euler totient φ(n) | 42642 |
| Square | 1818425449 |
| Cube | 77543116421707 |
| Square root | 206.501816 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 57 |
| Scientific notation | 4.2643 × |
42643 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand six hundred and forty-three |
| Binary (base 2) | 1010011010010011 |
| Octal (base 8) | 123223 |
| Hexadecimal (base 16) | A693 |
| Base 3 | 2011111101 |
| As time | 42643 seconds = 11 h 50 min 43 s |
Is 42643 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 3) | 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 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | 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 42643 a prime number?
Yes. 42643 is divisible only by 1 and itself.
What are the factors of 42643?
1, 42643.
What is 42643 in binary?
1010011010010011 (hexadecimal A693, octal 123223).
What is the square root of 42643?
About 206.5018.
Is 42643 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 42643?
42643 is a twin prime (42641 and 42643 are both prime); the 4457th prime number.