30
Cardinal	thirty
Ordinal	thirtieth
Numeral system
Factorization
Roman numeral	XXX
Binary	11110
Hexadecimal	1E

Mathematics

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

Other fields

• The atomic number of zinc.
• The number of edges on the regular icosahedron and the regular 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.
• Part of the name of:
  • Thirty odd foot of grunts, the band fronted by actor Russell Crowe
• The year AD 30.