The number 20443
20443 is a twin prime (20441 and 20443 are both prime) and the 2310th prime number. Its only divisors are 1 and 20443.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20443: a twin prime (20441 and 20443 are both prime); the 2310th prime number.
- 2
20443 is prime, so its only factors are 1 and 20443. It is the 2310th prime; the next prime is 20477 and the one before is 20441.
- 3
The divisors add up to 20444; without 20443 itself that is 1, so 20443 is deficient (1 is less than 20443). Euler's totient φ(20443) = 20442 numbers up to 20443 share no factor with it.
- 4
The digits of 20443 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 149 steps to reach 1.
20443 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 20444 |
| Euler totient φ(n) | 20442 |
| Square | 417916249 |
| Cube | 8543461878307 |
| Square root | 142.979019 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 149 |
| Scientific notation | 2.0443 × |
20443 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand four hundred and forty-three |
| Binary (base 2) | 100111111011011 |
| Octal (base 8) | 47733 |
| Hexadecimal (base 16) | 4FDB |
| Base 3 | 1001001011 |
| As time | 20443 seconds = 5 h 40 min 43 s |
Is 20443 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 5) | 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 20443 a prime number?
Yes. 20443 is divisible only by 1 and itself.
What are the factors of 20443?
1, 20443.
What is 20443 in binary?
100111111011011 (hexadecimal 4FDB, octal 47733).
What is the square root of 20443?
About 142.9790.
Is 20443 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 20443?
20443 is a twin prime (20441 and 20443 are both prime); the 2310th prime number.