The number 20983
20983 is a twin prime (20981 and 20983 are both prime) and the 2360th prime number. Its only divisors are 1 and 20983.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20983: a twin prime (20981 and 20983 are both prime); the 2360th prime number.
- 2
20983 is prime, so its only factors are 1 and 20983. It is the 2360th prime; the next prime is 21001 and the one before is 20981.
- 3
The divisors add up to 20984; without 20983 itself that is 1, so 20983 is deficient (1 is less than 20983). Euler's totient φ(20983) = 20982 numbers up to 20983 share no factor with it.
- 4
The digits of 20983 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 87 steps to reach 1.
20983 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 20984 |
| Euler totient φ(n) | 20982 |
| Square | 440286289 |
| Cube | 9238527202087 |
| Square root | 144.855100 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.0983 × |
20983 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and eighty-three |
| Binary (base 2) | 101000111110111 |
| Octal (base 8) | 50767 |
| Hexadecimal (base 16) | 51F7 |
| Base 3 | 1001210011 |
| As time | 20983 seconds = 5 h 49 min 43 s |
Is 20983 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 4) | 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 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 6) | 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 20983 a prime number?
Yes. 20983 is divisible only by 1 and itself.
What are the factors of 20983?
1, 20983.
What is 20983 in binary?
101000111110111 (hexadecimal 51F7, octal 50767).
What is the square root of 20983?
About 144.8551.
Is 20983 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 20983?
20983 is a twin prime (20981 and 20983 are both prime); the 2360th prime number.