What is 2?

2 is the:

• Smallest prime number: It's only divisible by 1 and itself. It's the only even prime number.
• Second natural number: Following 1 in the sequence of counting numbers.
• Second whole number: Including 0, 2 is the second whole number.
• Second integer: In the set of integers, it's the second positive integer.
• Cardinal number: Represents the quantity of two objects.
• Ordinal number: Represents the second position in a sequence (2nd).
• Binary digit (bit): In computer science, 2 represents a single bit.

It has several important mathematical properties and appears frequently in various mathematical contexts, including:

• Powers of 2: 2¹, 2², 2³, etc., are used extensively in computer science and mathematics.
• Even numbers: All even numbers are multiples of 2.

Its simplicity belies its significance as a foundational building block in mathematics and various other fields.