17 (number)
From Wikipedia, the free encyclopedia.
17 (seventeen) is the natural number following 16 and preceding 18.
| |||
| Cardinal | seventeen | ||
| Ordinal | seventeenth | ||
| Factorization | prime | ||
| Roman numeral | XVII | ||
| Binary | 10001 | ||
| Hexadecimal | 11 | ||
| Table of contents |
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2 In Science 3 In human affairs: Age 17 4 In other fields 5 External link |
In mathematics
Seventeen is the 7th smallest prime number, and is a Fermat prime. The next prime is nineteen, with which it comprises a twin prime.
There are exactly seventeen two-dimensional space (plane symmetry) groups. These are sometimes called wallpaper groups, as they represent the seventeen possible symmetry types that can be used for wallpaper.
According to hacker's lore, 17 is described at MIT as `the least random number'.
Like 41, the number 17 is a prime that yields primes in the polynomial n2 + n + p, for all positive n < p - 1.
In Science
Seventeen is also:
- The atomic number of chlorine.
- The Brodmann area defining the primary visual processing area of mammallian brains.
In human affairs: Age 17
- In the United States, the age at which one may donate blood and join the military voluntarily.
- In the United States, the age at which one may view R-rated movies without a parent's accompaniment according to MPAA standards.
In other fields
- The number of guns in a gun salute to U.S. Army, Air Force and Marine Corps Generals, and Navy and Coast Guard Admirals.
- A swear word in Swedish. The origin is controversial; though it is also known in the form "Sjutton tusen jaevlaer". (Seventeen thousand demons.)
- The maximum number of strokes of a Chinese radical.
- The number of syllables in a haiku.
- In the Nordic countries the seventeenth day of the year is considered the heart and/or the back of winter.
- Historical years: 17 A.D., 17 B.C, or 1917
In names
- The designation of United States Interstate 17, a freeway that in Arizona.
- In the title of At Seventeen, a famous song by Janis Ian.
- Seventeen, a magazine.
In trivia and the news
- The number of trees Dostoevsky could see out of the window of his cell, while he was in prison.
- The number of little porcelain pigs seized by police from the window ledge of Nancy Bennett of Leicester, Britain, on May 25, 1998; since she lived on the street of the big mosque, and worshippers there had complained.
- See also: Yellow Pig Day
External link