The number 82021
82021 is the 8022nd prime number. Its only divisors are 1 and 82021.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 82021: the 8022nd prime number.
- 2
82021 is prime, so its only factors are 1 and 82021. It is the 8022nd prime; the next prime is 82031 and the one before is 82013.
- 3
The divisors add up to 82022; without 82021 itself that is 1, so 82021 is deficient (1 is less than 82021). Euler's totient φ(82021) = 82020 numbers up to 82021 share no factor with it.
- 4
The digits of 82021 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 63 steps to reach 1.
82021 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 82022 |
| Euler totient φ(n) | 82020 |
| Square | 6727444441 |
| Cube | 551791720495261 |
| Square root | 286.393087 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 63 |
| Scientific notation | 8.2021 × |
82021 in other forms
| Form | Value |
|---|---|
| In words | eighty-two thousand and twenty-one |
| Binary (base 2) | 10100000001100101 |
| Octal (base 8) | 240145 |
| Hexadecimal (base 16) | 14065 |
| Base 3 | 11011111211 |
| As time | 82021 seconds = 22 h 47 min 1 s |
Is 82021 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 5) | 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 1) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 82021 a prime number?
Yes. 82021 is divisible only by 1 and itself.
What are the factors of 82021?
1, 82021.
What is 82021 in binary?
10100000001100101 (hexadecimal 14065, octal 240145).
What is the square root of 82021?
About 286.3931.
Is 82021 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 82021?
82021 is the 8022nd prime number.