2 (two) is a number, numeral and digit. It is the natural number following 1 and preceding 3. It is the smallest and only even prime number.
Because it forms the basis of a duality, it has religious and spiritual significance in many cultures.
Two is most commonly a determiner used with plural countable nouns, as in two days or I'll take these two.[1] Two is a noun when it refers to the number two as in two plus two is four.
The word two is derived from the Old English words twā (feminine), tū (neuter), and twēġen (masculine, which survives today in the form twain).[2]
The pronunciation /tuː/, like that of who is due to the labialization of the vowel by the w, which then disappeared before the related sound. The successive stages of pronunciation for the Old English twā would thus be /twɑː/, /twɔː/, /twoː/, /twuː/, and finally /tuː/.[2]
An integer is determined to be even if it is divisible by two. For integers written in a numeral system based on an even number such as decimal, divisibility by two is easily tested by merely looking at the last digit. If it is even, then the whole number is even. When written in the decimal system, all multiple of 2 will end in 0, 2, 4, 6, or 8.[3]