The number 82081
82081 is a composite number with 4 divisors. Its prime factorisation is 79 × 1039. Divisors (4): 1, 79, 1039, 82081.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 82081: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 79 × 1039, the product of two primes.
- 2
82081 is composite. Its prime factorisation is
- 3
The divisors add up to 83200; without 82081 itself that is 1119, so 82081 is deficient (1119 is less than 82081). Euler's totient φ(82081) = 80964 numbers up to 82081 share no factor with it.
- 4
The digits of 82081 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 182 steps to reach 1.
LaTeX source of the formulas on this page
\[ 82081 = 79 \times 1039 \]
82081 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 83200 |
| Euler totient φ(n) | 80964 |
| Square | 6737290561 |
| Cube | 553003546537441 |
| Square root | 286.497818 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 182 |
| Scientific notation | 8.2081 × |
82081 in other forms
| Form | Value |
|---|---|
| In words | eighty-two thousand and eighty-one |
| Binary (base 2) | 10100000010100001 |
| Octal (base 8) | 240241 |
| Hexadecimal (base 16) | 140A1 |
| Base 3 | 11011121001 |
| As time | 82081 seconds = 22 h 48 min 1 s |
Is 82081 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 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 1) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 82081 a prime number?
No. 82081 = 79 × 1039, so it is divisible by 79.
What are the factors of 82081?
1, 79, 1039, 82081.
What is 82081 in binary?
10100000010100001 (hexadecimal 140A1, octal 240241).
What is the square root of 82081?
About 286.4978.
Is 82081 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 82081?
82081 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 79 × 1039, the product of two primes.