The number 90009
90009 is a palindrome: it reads 90009 backwards too. Its prime factorisation is × 73 × 137. Divisors (12): 1, 3, 9, 73, 137, 219, 411, 657, 1233, 10001, 30003, 90009.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 90009: a palindrome: it reads 90009 backwards too.
- 2
90009 is composite. Its prime factorisation is
- 3
The divisors add up to 132756; without 90009 itself that is 42747, so 90009 is deficient (42747 is less than 90009). Euler's totient φ(90009) = 58752 numbers up to 90009 share no factor with it.
- 4
The digits of 90009 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 89 steps to reach 1.
LaTeX source of the formulas on this page
\[ 90009 = 3^{2} \times 73 \times 137 \]90009 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 132756 |
| Euler totient φ(n) | 58752 |
| Square | 8101620081 |
| Cube | 729218721870729 |
| Square root | 300.015000 (= 3√10001) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 89 |
| Scientific notation | 9.0009 × |
90009 in other forms
| Form | Value |
|---|---|
| In words | ninety thousand and nine |
| Binary (base 2) | 10101111110011001 |
| Octal (base 8) | 257631 |
| Hexadecimal (base 16) | 15F99 |
| Base 3 | 11120110200 |
| As time | 90009 seconds = 25 h 0 min 9 s |
Is 90009 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 (90009 ÷ 3 = 30003) | 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 3) | 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 | No (remainder 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (90009 ÷ 9 = 10001) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 90009 a prime number?
No. 90009 = × 73 × 137, so it is divisible by 3.
What are the factors of 90009?
1, 3, 9, 73, 137, 219, 411, 657, 1233, 10001, 30003, 90009.
What is 90009 in binary?
10101111110011001 (hexadecimal 15F99, octal 257631).
What is the square root of 90009?
About 300.0150, exactly 3√10001.
Is 90009 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 90009?
90009 is a palindrome: it reads 90009 backwards too.