The number 80005
80005 is a composite number with 4 divisors. Its prime factorisation is 5 × 16001. Divisors (4): 1, 5, 16001, 80005.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 80005: a semiprime: 5 × 16001, the product of two primes.
- 2
80005 is composite. Its prime factorisation is
- 3
The divisors add up to 96012; without 80005 itself that is 16007, so 80005 is deficient (16007 is less than 80005). Euler's totient φ(80005) = 64000 numbers up to 80005 share no factor with it.
- 4
The digits of 80005 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 80005 = 5 \times 16001 \]
80005 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 96012 |
| Euler totient φ(n) | 64000 |
| Square | 6400800025 |
| Cube | 512096006000125 |
| Square root | 282.851551 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 169 |
| Scientific notation | 8.0005 × |
80005 in other forms
| Form | Value |
|---|---|
| In words | eighty thousand and five |
| Binary (base 2) | 10011100010000101 |
| Octal (base 8) | 234205 |
| Hexadecimal (base 16) | 13885 |
| Base 3 | 11001202011 |
| As time | 80005 seconds = 22 h 13 min 25 s |
Is 80005 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 | Yes (80005 ÷ 5 = 16001) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 80005 a prime number?
No. 80005 = 5 × 16001, so it is divisible by 5.
What are the factors of 80005?
1, 5, 16001, 80005.
What is 80005 in binary?
10011100010000101 (hexadecimal 13885, octal 234205).
What is the square root of 80005?
About 282.8516.
Is 80005 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 80005?
80005 is a semiprime: 5 × 16001, the product of two primes.