The number 80018
80018 is a composite number with 4 divisors. Its prime factorisation is 2 × 40009. Divisors (4): 1, 2, 40009, 80018.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 80018: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 40009, the product of two primes.
- 2
80018 is composite. Its prime factorisation is
- 3
The divisors add up to 120030; without 80018 itself that is 40012, so 80018 is deficient (40012 is less than 80018). Euler's totient φ(80018) = 40008 numbers up to 80018 share no factor with it.
- 4
The digits of 80018 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 80018 = 2 \times 40009 \]
80018 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 120030 |
| Euler totient φ(n) | 40008 |
| Square | 6402880324 |
| Cube | 512345677765832 |
| Square root | 282.874530 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 94 |
| Scientific notation | 8.0018 × |
80018 in other forms
| Form | Value |
|---|---|
| In words | eighty thousand and eighteen |
| Binary (base 2) | 10011100010010010 |
| Octal (base 8) | 234222 |
| Hexadecimal (base 16) | 13892 |
| Base 3 | 11001202122 |
| As time | 80018 seconds = 22 h 13 min 38 s |
Is 80018 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (80018 ÷ 2 = 40009) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 2) | 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 8) | 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 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 80018 a prime number?
No. 80018 = 2 × 40009, so it is divisible by 2.
What are the factors of 80018?
1, 2, 40009, 80018.
What is 80018 in binary?
10011100010010010 (hexadecimal 13892, octal 234222).
What is the square root of 80018?
About 282.8745.
Is 80018 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 80018?
80018 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 40009, the product of two primes.