The number 2018
2018 is a composite number with 4 divisors. Its prime factorisation is 2 × 1009. Divisors (4): 1, 2, 1009, 2018.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2018: a semiprime: 2 × 1009, the product of two primes.
- 2
2018 is composite. Its prime factorisation is
- 3
The divisors add up to 3030; without 2018 itself that is 1012, so 2018 is deficient (1012 is less than 2018). Euler's totient φ(2018) = 1008 numbers up to 2018 share no factor with it.
- 4
The digits of 2018 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 112 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2018 = 2 \times 1009 \]
2018 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 3030 |
| Euler totient φ(n) | 1008 |
| Square | 4072324 |
| Cube | 8217949832 |
| Square root | 44.922155 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 112 |
| Scientific notation | 2.018 × |
2018 in other forms
| Form | Value |
|---|---|
| In words | two thousand and eighteen |
| Roman numerals | MMXVIII |
| Binary (base 2) | 11111100010 |
| Octal (base 8) | 3742 |
| Hexadecimal (base 16) | 7E2 |
| Base 3 | 2202202 |
| As time | 2018 seconds = 33 min 38 s |
Is 2018 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (2018 ÷ 2 = 1009) | 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 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 5) | 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 2018 a prime number?
No. 2018 = 2 × 1009, so it is divisible by 2.
What are the factors of 2018?
1, 2, 1009, 2018.
What is 2018 in binary?
11111100010 (hexadecimal 7E2, octal 3742).
What is the square root of 2018?
About 44.9222.
What is 2018 in Roman numerals?
MMXVIII.
Is 2018 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 2018?
2018 is a semiprime: 2 × 1009, the product of two primes.