The number 80909
80909 is a twin prime (80909 and 80911 are both prime) and the 7917th prime number. Its only divisors are 1 and 80909.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 80909: a twin prime (80909 and 80911 are both prime); the 7917th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
80909 is prime, so its only factors are 1 and 80909. It is the 7917th prime; the next prime is 80911 and the one before is 80897.
- 3
The divisors add up to 80910; without 80909 itself that is 1, so 80909 is deficient (1 is less than 80909). Euler's totient φ(80909) = 80908 numbers up to 80909 share no factor with it.
- 4
The digits of 80909 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
80909 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 80910 |
| Euler totient φ(n) | 80908 |
| Square | 6546266281 |
| Cube | 529651858529429 |
| Square root | 284.445074 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 138 |
| Scientific notation | 8.0909 × |
80909 in other forms
| Form | Value |
|---|---|
| In words | eighty thousand nine hundred and nine |
| Binary (base 2) | 10011110000001101 |
| Octal (base 8) | 236015 |
| Hexadecimal (base 16) | 13C0D |
| Base 3 | 11002222122 |
| As time | 80909 seconds = 22 h 28 min 29 s |
Is 80909 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 | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 4) | 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 80909 a prime number?
Yes. 80909 is divisible only by 1 and itself.
What are the factors of 80909?
1, 80909.
What is 80909 in binary?
10011110000001101 (hexadecimal 13C0D, octal 236015).
What is the square root of 80909?
About 284.4451.
Is 80909 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 80909?
80909 is a twin prime (80909 and 80911 are both prime); the 7917th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.