The number 81006
81006 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 23 × 587. Divisors (16): 1, 2, 3, 6, 23, 46, 69, 138, 587, 1174, 1761, 3522, 13501, 27002, 40503, 81006.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
81006 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
81006 is composite. Its prime factorisation is
- 3
The divisors add up to 169344; without 81006 itself that is 88338, so 81006 is abundant (88338 is more than 81006). Euler's totient φ(81006) = 25784 numbers up to 81006 share no factor with it.
- 4
The digits of 81006 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 213 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81006 = 2 \times 3 \times 23 \times 587 \]
81006 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 169344 |
| Euler totient φ(n) | 25784 |
| Square | 6561972036 |
| Cube | 531559106748216 |
| Square root | 284.615530 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 213 |
| Scientific notation | 8.1006 × |
81006 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand and six |
| Binary (base 2) | 10011110001101110 |
| Octal (base 8) | 236156 |
| Hexadecimal (base 16) | 13C6E |
| Base 3 | 11010010020 |
| As time | 81006 seconds = 22 h 30 min 6 s |
Is 81006 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81006 ÷ 2 = 40503) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (81006 ÷ 3 = 27002) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (81006 ÷ 6 = 13501) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 6) | 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 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81006 a prime number?
No. 81006 = 2 × 3 × 23 × 587, so it is divisible by 2.
What are the factors of 81006?
1, 2, 3, 6, 23, 46, 69, 138, 587, 1174, 1761, 3522, 13501, 27002, 40503, 81006.
What is 81006 in binary?
10011110001101110 (hexadecimal 13C6E, octal 236156).
What is the square root of 81006?
About 284.6155.
Is 81006 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 81006?
It is a composite number with 16 divisors.