The number 91009
91009 is the 8803rd prime number. Its only divisors are 1 and 91009.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 91009: the 8803rd prime number.
- 2
91009 is prime, so its only factors are 1 and 91009. It is the 8803rd prime; the next prime is 91019 and the one before is 90997.
- 3
The divisors add up to 91010; without 91009 itself that is 1, so 91009 is deficient (1 is less than 91009). Euler's totient φ(91009) = 91008 numbers up to 91009 share no factor with it.
- 4
The digits of 91009 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 89 steps to reach 1.
91009 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 91010 |
| Euler totient φ(n) | 91008 |
| Square | 8282638081 |
| Cube | 753794609113729 |
| Square root | 301.676980 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 89 |
| Scientific notation | 9.1009 × |
91009 in other forms
| Form | Value |
|---|---|
| In words | ninety-one thousand and nine |
| Binary (base 2) | 10110001110000001 |
| Octal (base 8) | 261601 |
| Hexadecimal (base 16) | 16381 |
| Base 3 | 11121211201 |
| As time | 91009 seconds = 25 h 16 min 49 s |
Is 91009 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 1) | 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 1) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 91009 a prime number?
Yes. 91009 is divisible only by 1 and itself.
What are the factors of 91009?
1, 91009.
What is 91009 in binary?
10110001110000001 (hexadecimal 16381, octal 261601).
What is the square root of 91009?
About 301.6770.
Is 91009 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 91009?
91009 is the 8803rd prime number.