The number 2 is a natural number following 1 and preceding 3. It is the smallest and the only even prime number. It also holds significance in mathematics as the first Ramanujan prime, the first superior highly composite number, and the first colossally abundant number. Some properties and facts about the number 2 include:

• It is the smallest and only even prime number.
• Any integer divisible by 2 is considered even.
• In a number system with base 10, multiples of 2 end in 0, 2, 4, 6, or 8.
• The binary numeral system uses 2 as its base, fundamental to computing.
• The word "two" is used as both a determiner and a noun in English.
• The symbol for the number 2 evolved from ancient scripts such as the Indic Brahmic script.

In science, 2 represents:

• The number of electrons in the innermost shell of an atom.
• The atomic number of helium.

The number 2 is deeply embedded in culture, religion, and language, often representing duality and pairs in various contexts.