The number 81828
81828 is a composite number with 18 divisors. Its prime factorisation is × × 2273. Divisors (18): 1, 2, 3, 4, 6, 9, 12, 18, 36, 2273, 4546, 6819, 9092, 13638, 20457, 27276 … 81828.
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How to work it out
- 1
81828 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
81828 is composite. Its prime factorisation is
- 3
The divisors add up to 206934; without 81828 itself that is 125106, so 81828 is abundant (125106 is more than 81828). Euler's totient φ(81828) = 27264 numbers up to 81828 share no factor with it.
- 4
The digits of 81828 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81828 = 2^{2} \times 3^{2} \times 2273 \]81828 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 206934 |
| Euler totient φ(n) | 27264 |
| Square | 6695821584 |
| Cube | 547905688575552 |
| Square root | 286.055939 (= 6√2273) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 76 |
| Scientific notation | 8.1828 × |
81828 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand eight hundred and twenty-eight |
| Binary (base 2) | 10011111110100100 |
| Octal (base 8) | 237644 |
| Hexadecimal (base 16) | 13FA4 |
| Base 3 | 11011020200 |
| As time | 81828 seconds = 22 h 43 min 48 s |
Is 81828 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81828 ÷ 2 = 40914) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (81828 ÷ 3 = 27276) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (81828 ÷ 4 = 20457) | 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 | Yes (81828 ÷ 6 = 13638) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (81828 ÷ 9 = 9092) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | 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 | Yes (81828 ÷ 12 = 6819) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81828 a prime number?
No. 81828 = × × 2273, so it is divisible by 2.
What are the factors of 81828?
1, 2, 3, 4, 6, 9, 12, 18, 36, 2273, 4546, 6819, 9092, 13638, 20457, 27276, 40914, 81828.
What is 81828 in binary?
10011111110100100 (hexadecimal 13FA4, octal 237644).
What is the square root of 81828?
About 286.0559, exactly 6√2273.
Is 81828 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 81828?
It is a composite number with 18 divisors.