The number 81672
81672 is a composite number with 32 divisors. Its prime factorisation is × 3 × 41 × 83. Divisors (32): 1, 2, 3, 4, 6, 8, 12, 24, 41, 82, 83, 123, 164, 166, 246, 249 … 81672.
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How to work it out
- 1
What is special about 81672: a Harshad number: divisible by its digit sum 24.
- 2
81672 is composite. Its prime factorisation is
- 3
The divisors add up to 211680; without 81672 itself that is 130008, so 81672 is abundant (130008 is more than 81672). Euler's totient φ(81672) = 26240 numbers up to 81672 share no factor with it.
- 4
The digits of 81672 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 89 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81672 = 2^{3} \times 3 \times 41 \times 83 \]81672 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 211680 |
| Euler totient φ(n) | 26240 |
| Square | 6670315584 |
| Cube | 544778014376448 |
| Square root | 285.783135 (= 2√20418) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 89 |
| Scientific notation | 8.1672 × |
81672 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand six hundred and seventy-two |
| Binary (base 2) | 10011111100001000 |
| Octal (base 8) | 237410 |
| Hexadecimal (base 16) | 13F08 |
| Base 3 | 11011000220 |
| As time | 81672 seconds = 22 h 41 min 12 s |
Is 81672 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81672 ÷ 2 = 40836) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (81672 ÷ 3 = 27224) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (81672 ÷ 4 = 20418) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (81672 ÷ 6 = 13612) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 (81672 ÷ 8 = 10209) | 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 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (81672 ÷ 12 = 6806) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81672 a prime number?
No. 81672 = × 3 × 41 × 83, so it is divisible by 2.
What are the factors of 81672?
1, 2, 3, 4, 6, 8, 12, 24, 41, 82, 83, 123, 164, 166, 246, 249, 328, 332, 492, 498, 664, 984, 996, 1992, 3403, 6806, 10209, 13612, 20418, 27224, 40836, 81672.
What is 81672 in binary?
10011111100001000 (hexadecimal 13F08, octal 237410).
What is the square root of 81672?
About 285.7831, exactly 2√20418.
Is 81672 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 81672?
81672 is a Harshad number: divisible by its digit sum 24.