What is 4?

The number 4 has several interesting properties:

  • Arithmetic: It's an even number, a composite number (meaning it has factors other than 1 and itself – its factors are 1, 2, and 4), and a perfect square (2² = 4).

  • Geometry: It's the number of sides of a square, and is associated with quadrilaterals more generally. Four points define a tetrahedron (a 3-dimensional shape).

  • Number Theory: It's the smallest composite number, and the only even prime number's square. It appears in many mathematical formulas and sequences.

  • Cultural Significance: In many cultures, four represents stability, strength, and the four elements (earth, air, fire, water). It's often associated with the cardinal directions (north, south, east, west).

  • Other: In computer science, 4 bits make a nibble. Many programming languages use 4 bytes to represent an integer.

These are just a few examples – the significance of the number 4 depends heavily on the context.