The number 82720
82720 is a composite number with 48 divisors. Its prime factorisation is × 5 × 11 × 47. Divisors (48): 1, 2, 4, 5, 8, 10, 11, 16, 20, 22, 32, 40, 44, 47, 55, 80 … 82720.
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How to work it out
- 1
82720 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
82720 is composite. Its prime factorisation is
- 3
The divisors add up to 217728; without 82720 itself that is 135008, so 82720 is abundant (135008 is more than 82720). Euler's totient φ(82720) = 29440 numbers up to 82720 share no factor with it.
- 4
The digits of 82720 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 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 82720 = 2^{5} \times 5 \times 11 \times 47 \]82720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 217728 |
| Euler totient φ(n) | 29440 |
| Square | 6842598400 |
| Cube | 566019739648000 |
| Square root | 287.610848 (= 4√5170) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 58 |
| Scientific notation | 8.272 × |
82720 in other forms
| Form | Value |
|---|---|
| In words | eighty-two thousand seven hundred and twenty |
| Binary (base 2) | 10100001100100000 |
| Octal (base 8) | 241440 |
| Hexadecimal (base 16) | 14320 |
| Base 3 | 11012110201 |
| As time | 82720 seconds = 22 h 58 min 40 s |
Is 82720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (82720 ÷ 2 = 41360) | 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 | Yes (82720 ÷ 4 = 20680) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (82720 ÷ 5 = 16544) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 | Yes (82720 ÷ 8 = 10340) | 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 | Yes (82720 ÷ 10 = 8272) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (82720 ÷ 11 = 7520) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 82720 a prime number?
No. 82720 = × 5 × 11 × 47, so it is divisible by 2.
What are the factors of 82720?
1, 2, 4, 5, 8, 10, 11, 16, 20, 22, 32, 40, 44, 47, 55, 80, 88, 94, 110, 160, 176, 188, 220, 235, 352, 376, 440, 470, 517, 752, 880, 940, 1034, 1504, 1760, 1880, 2068, 2585, 3760, 4136, 5170, 7520, 8272, 10340, 16544, 20680, 41360, 82720.
What is 82720 in binary?
10100001100100000 (hexadecimal 14320, octal 241440).
What is the square root of 82720?
About 287.6108, exactly 4√5170.
Is 82720 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 82720?
It is a composite number with 48 divisors.