Some facts about the number 18 are that it is the only positive number that is equal to the sum of the digits multiplied by two, it is the atomic number of Argon and there are 18 holes on most golf courses. The number 18 is also the age at which United States citizens are legally allowed to vote.
While the first fact may sound confusing, broken down it is easy to understand. Twice the sum of its digits simply means if one adds the digits 1 and 8, the answer is nine. Nine multiplied by 2 is equal to the number 18.
There are many other interesting and obscure facts about this number:
- There are 18 years in the Saros cycle of the sun and moon eclipses.
- In the Talmud, which is a holy book in the Jewish religion, age 18 is designated as the appropriate age to get married.
- In Australian rules for football, during play there are always 18 players on the field.
- The novel "Ulysses" by James Joyce has 18 chapters.
- "I'm Eighteen" is Alice Cooper's first top 10 hit single. This song is from their "Love It to Death" album, released in 1971.
- A comfortable room temperature is 18 degrees Celsius, which translates to 64.4 degrees Fahrenheit.