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2

2 is the natural number that follows 1 and precedes 3. It is an even number and a prime number—the only even prime and the smallest prime.

In decimal notation, 2 is written as the digit 2. In other systems, it appears as 10

Mathematically, 2 is the base of the binary system used in computing and the smallest factor of

Science uses the number in several ways: helium has atomic number 2; diatomic molecules such as H2,

In culture, two often denotes a pair or duality, as in duo or double. In language and

Overall, 2 is a fundamental building block in arithmetic, science, and everyday language, appearing in counting,

in
binary
and
II
in
Roman
numerals.
any
even
integer.
It
is
the
first
prime,
and
its
multiplication
table
begins
with
1×2
and
2×2.
N2,
and
O2
are
common
in
chemistry.
mathematics,
the
concept
of
pairings
and
dual
relationships
frequently
centers
on
the
idea
of
two
units
or
elements.
measurement,
and
digital
information.