30 (number)
30 (thirty) is the natural number following 29 and preceding 31.
Template:Numbers 30s | |
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.
30 is the largest number such that coprimes smaller than itself are also prime. It is a Harshad number.
The Chinese word numeral for thirty is 三十.
A polygon with thirty sides is called a tricontagon. Both an icosahedron and a dodecahedron have 30 edges.
In other fields
30 is:
- The atomic number of zinc.
- The house number of 30 St Mary Axe (The Gherkin)
- The number of days in the months April, June, September and November.
- In years of marriage, the pearl wedding anniversary.
- The code for international direct dial phone calls to Greece.
- The duration of the Thirty Years' War.
- The designation of Interstate 30, a freeway that runs from Texas to Arkansas.
- Used to indicate the end of a wire service story.
- The number of tracks on The Beatles' eponymous album, usually known as The White Album.
- Part of the name of:
- Thirty odd foot of grunts, the band fronted by actor Russell Crowe
- In the title of the movie 13 Going on 30, starring Jennifer Garner.
- In the title of the Food Network show 30 Minute Meals.
- Historical years: 30 A.D., 30 B.C., or 1930
- The number of cars in the Nintendo 64 game F-Zero X.