The number 28006
28006 is a composite number with 16 divisors. Its prime factorisation is 2 × 11 × 19 × 67. Divisors (16): 1, 2, 11, 19, 22, 38, 67, 134, 209, 418, 737, 1273, 1474, 2546, 14003, 28006.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
28006 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
28006 is composite. Its prime factorisation is
- 3
The divisors add up to 48960; without 28006 itself that is 20954, so 28006 is deficient (20954 is less than 28006). Euler's totient φ(28006) = 11880 numbers up to 28006 share no factor with it.
- 4
The digits of 28006 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 33 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28006 = 2 \times 11 \times 19 \times 67 \]
28006 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 48960 |
| Euler totient φ(n) | 11880 |
| Square | 784336036 |
| Cube | 21966115024216 |
| Square root | 167.349933 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 33 |
| Scientific notation | 2.8006 × |
28006 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand and six |
| Binary (base 2) | 110110101100110 |
| Octal (base 8) | 66546 |
| Hexadecimal (base 16) | 6D66 |
| Base 3 | 1102102021 |
| As time | 28006 seconds = 7 h 46 min 46 s |
Is 28006 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28006 ÷ 2 = 14003) | 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 | 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 | No (remainder 4) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 | Yes (28006 ÷ 11 = 2546) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28006 a prime number?
No. 28006 = 2 × 11 × 19 × 67, so it is divisible by 2.
What are the factors of 28006?
1, 2, 11, 19, 22, 38, 67, 134, 209, 418, 737, 1273, 1474, 2546, 14003, 28006.
What is 28006 in binary?
110110101100110 (hexadecimal 6D66, octal 66546).
What is the square root of 28006?
About 167.3499.
Is 28006 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 28006?
It is a composite number with 16 divisors.