The 30 (number) reference article from the English Wikipedia on 24-Apr-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

30 (number)

30 (thirty) is the natural number following 29 and preceding 31.

List of numbers — Integers << 30 31 32 33 34 35 36 37 38 39 >>
Cardinal	thirty
Ordinal	thirtieth
Numeral system
Factorization
Divisors	2, 3, 5, 6, 10, 15
Roman numeral	XXX
Binary	11110
Hexadecimal	1E

In mathematics

It is a primorial as well as the sum of the squares of the integers 1, 2, 3 and 4. It is the first sphenic number and the first Giuga number. It is the sum of the first four squares, which makes it a square pyramidal number.

The Chinese word numeral for thirty is 三十; a polygon with thirty sides is called a tricegon. [1]

In other fields

Thirty is:

• The atomic number of zinc.
• The number of edges on an icosahedron or a dodecahedron.
• The house number of 30 St Mary Axe (The Gherkin)
• The number of days in the months April, June, September and November.
• The number of moons of the planet Saturn.
• In years of marriage, the pearl wedding anniversary.
• The code for international direct dial phone calls to Greece.
• The designation of Interstate 30, a freeway that runs from Texas to Arkansas.
• Used to indicate the end of a wire service story.
• Part of the name of:
  • Thirty odd foot of grunts, the band fronted by actor Russell Crowe
• Historical years: 30 A.D., 30 B.C, or 1930

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