# 2 (number)

(Redirected from Two)
 ← 1 2 3 →
Cardinaltwo
Ordinal2nd
(second)
Factorizationprime
Divisors1, 2
Greek numeralΒ´
Roman numeralII
Roman numeral (unicode)Ⅱ, ⅱ
Greek prefixdi-
Latin prefixduo- bi-
Old English prefixtwi-
Binary102
Ternary23
Quaternary24
Quinary25
Senary26
Octal28
Duodecimal212
Vigesimal220
Base 36236
Greek numeralβ'
Arabic٢
Urdu
Ge'ez
Bengali
Chinese numeral二，弍，贰，貳
Devanāgarī
Telugu
Tamil
Hebrewב (Bet)
Khmer
Korean이，둘
Thai

2 (Two; ) is a number, numeral, and glyph. It is the number after 1 (one) and the number before 3 (three). In Roman numerals, it is II.

## In mathematics

Two has many meanings in math. For example: ${\displaystyle 1+1=2}$.[1] An integer is even if half of it equals an integer. If the last digit of a number is even, then the number is even. This means that if you multiply 2 times anything, it will end in 0, 2, 4, 6, or 8.

Two is the smallest, first, and only even prime number. The next prime number is three. Two and three are the only prime numbers next to each other. The even numbers above two are not prime because they are divisible by 2.

Fractions with 2 in the bottom do not yield infinite.

Two is the framework of the binary system used in computers. The binary way is the simplest system of numbers where natural numbers (the numbers used to count) can be written.

Two also has the unique property that 2+2 = 2·2 = 22 and 2! + 2 = 22.

Powers of two are important to computer science.

The square root of two was the first known irrational number.

## References

1. Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 41–44