The number 2009
2009 is a composite number with 6 divisors. Its prime factorisation is Ć 41. Divisors (6): 1, 7, 41, 49, 287, 2009.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
2009 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
2009 is composite. Its prime factorisation is
- 3
The divisors add up to 2394; without 2009 itself that is 385, so 2009 is deficient (385 is less than 2009). Euler's totient Ļ(2009) = 1680 numbers up to 2009 share no factor with it.
- 4
The digits of 2009 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 24 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2009 = 7^{2} \times 41 \]2009 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 2394 |
| Euler totient Ļ(n) | 1680 |
| Square | 4036081 |
| Cube | 8108486729 |
| Square root | 44.821870 (= 7ā41) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 24 |
| Scientific notation | 2.009 Ć |
2009 in other forms
| Form | Value |
|---|---|
| In words | two thousand and nine |
| Roman numerals | MMIX |
| Binary (base 2) | 11111011001 |
| Octal (base 8) | 3731 |
| Hexadecimal (base 16) | 7D9 |
| Base 3 | 2202102 |
| As time | 2009 seconds = 33 min 29 s |
Is 2009 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 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (2009 Ć· 7 = 287) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2009 a prime number?
No. 2009 = Ć 41, so it is divisible by 7.
What are the factors of 2009?
1, 7, 41, 49, 287, 2009.
What is 2009 in binary?
11111011001 (hexadecimal 7D9, octal 3731).
What is the square root of 2009?
About 44.8219, exactly 7ā41.
What is 2009 in Roman numerals?
MMIX.
Is 2009 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 2009?
It is a composite number with 6 divisors.