The number 82005
82005 is a composite number with 32 divisors. Its prime factorisation is 3 × 5 × 7 × 11 × 71. Divisors (32): 1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 71, 77, 105, 165, 213, 231 … 82005.
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How to work it out
- 1
What is special about 82005: a Harshad number: divisible by its digit sum 15.
- 2
82005 is composite. Its prime factorisation is
- 3
The divisors add up to 165888; without 82005 itself that is 83883, so 82005 is abundant (83883 is more than 82005). Euler's totient φ(82005) = 33600 numbers up to 82005 share no factor with it.
- 4
The digits of 82005 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 82005 = 3 \times 5 \times 7 \times 11 \times 71 \]
82005 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 165888 |
| Euler totient φ(n) | 33600 |
| Square | 6724820025 |
| Cube | 551468866150125 |
| Square root | 286.365152 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 58 |
| Scientific notation | 8.2005 × |
82005 in other forms
| Form | Value |
|---|---|
| In words | eighty-two thousand and five |
| Binary (base 2) | 10100000001010101 |
| Octal (base 8) | 240125 |
| Hexadecimal (base 16) | 14055 |
| Base 3 | 11011111020 |
| As time | 82005 seconds = 22 h 46 min 45 s |
Is 82005 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 | Yes (82005 ÷ 3 = 27335) | 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 | Yes (82005 ÷ 5 = 16401) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (82005 ÷ 7 = 11715) | 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 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (82005 ÷ 11 = 7455) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 82005 a prime number?
No. 82005 = 3 × 5 × 7 × 11 × 71, so it is divisible by 3.
What are the factors of 82005?
1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 71, 77, 105, 165, 213, 231, 355, 385, 497, 781, 1065, 1155, 1491, 2343, 2485, 3905, 5467, 7455, 11715, 16401, 27335, 82005.
What is 82005 in binary?
10100000001010101 (hexadecimal 14055, octal 240125).
What is the square root of 82005?
About 286.3652.
Is 82005 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 82005?
82005 is a Harshad number: divisible by its digit sum 15.