simple:Two

For the year 2, see 2. For some fictional characters, see Number Two.

Two (2) is the natural number following one and preceding three.

Two has many properties in mathematics:

x+x = 2·x
x·x = x2
Two is a Fibonacci number and a primorial, as well as its own factorial.

Cultural meaning

The duality of all things is an important notion in most cultures and religions. The most common philosophical dichotomy is perhaps the one of good and evil, but there are many others. See dualism for an overview. In Hegelianian dialectic, the process of antithesis creates two perspectives from one.

Two is a good number in Chinese culture. There is a Chinese saying "good things come in pairs". It is common to use double symbols in product brandnames, e.g. double happiness, double coin, double elephants etc. Cantonese people like the number two because it sounds the same as the word "easy" (易) in Cantonese.

In Finland, two candles are lit on Independence Day. Putting them on the windowsill invokes the symbolical meaning of division, and thus independence.

In the philosophy of Pythagoras, the dyad is the second thing created (see the article monad for details).

The number 2 is sometimes used as a shorthand for "to". One common example is computer software which translates data from one format into another, such as dvi2ps and texi2roff.

See also: list of famous pairs, zero, one, two, three, four, integer, list of numbers.