The number 20743
20743 is the 2335th prime number. Its only divisors are 1 and 20743.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20743: the 2335th prime number.
- 2
20743 is prime, so its only factors are 1 and 20743. It is the 2335th prime; the next prime is 20747 and the one before is 20731.
- 3
The divisors add up to 20744; without 20743 itself that is 1, so 20743 is deficient (1 is less than 20743). Euler's totient φ(20743) = 20742 numbers up to 20743 share no factor with it.
- 4
The digits of 20743 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 61 steps to reach 1.
20743 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 20744 |
| Euler totient φ(n) | 20742 |
| Square | 430272049 |
| Cube | 8925133112407 |
| Square root | 144.024304 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 61 |
| Scientific notation | 2.0743 × |
20743 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and forty-three |
| Binary (base 2) | 101000100000111 |
| Octal (base 8) | 50407 |
| Hexadecimal (base 16) | 5107 |
| Base 3 | 1001110021 |
| As time | 20743 seconds = 5 h 45 min 43 s |
Is 20743 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 2) | 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 7) | 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 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 20743 a prime number?
Yes. 20743 is divisible only by 1 and itself.
What are the factors of 20743?
1, 20743.
What is 20743 in binary?
101000100000111 (hexadecimal 5107, octal 50407).
What is the square root of 20743?
About 144.0243.
Is 20743 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 20743?
20743 is the 2335th prime number.