The number 81675
81675 is a composite number with 36 divisors. Its prime factorisation is × × . Divisors (36): 1, 3, 5, 9, 11, 15, 25, 27, 33, 45, 55, 75, 99, 121, 135, 165 … 81675.
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How to work it out
- 1
What is special about 81675: a Harshad number: divisible by its digit sum 27.
- 2
81675 is composite. Its prime factorisation is
- 3
The divisors add up to 164920; without 81675 itself that is 83245, so 81675 is abundant (83245 is more than 81675). Euler's totient φ(81675) = 39600 numbers up to 81675 share no factor with it.
- 4
The digits of 81675 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
\[ 81675 = 3^{3} \times 5^{2} \times 11^{2} \]81675 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 164920 |
| Euler totient φ(n) | 39600 |
| Square | 6670805625 |
| Cube | 544838049421875 |
| Square root | 285.788383 (= 165√3) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 76 |
| Scientific notation | 8.1675 × |
81675 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand six hundred and seventy-five |
| Binary (base 2) | 10011111100001011 |
| Octal (base 8) | 237413 |
| Hexadecimal (base 16) | 13F0B |
| Base 3 | 11011001000 |
| As time | 81675 seconds = 22 h 41 min 15 s |
Is 81675 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 (81675 ÷ 3 = 27225) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (81675 ÷ 5 = 16335) | 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 | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (81675 ÷ 9 = 9075) | 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 (81675 ÷ 11 = 7425) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81675 a prime number?
No. 81675 = × × , so it is divisible by 3.
What are the factors of 81675?
1, 3, 5, 9, 11, 15, 25, 27, 33, 45, 55, 75, 99, 121, 135, 165, 225, 275, 297, 363, 495, 605, 675, 825, 1089, 1485, 1815, 2475, 3025, 3267, 5445, 7425, 9075, 16335, 27225, 81675.
What is 81675 in binary?
10011111100001011 (hexadecimal 13F0B, octal 237413).
What is the square root of 81675?
About 285.7884, exactly 165√3.
Is 81675 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 81675?
81675 is a Harshad number: divisible by its digit sum 27.