Why is the data type int, representing a 32-bit number, unable to store a value exceeding approximately 2 billion?

The int type in Java occupies 32 bits and stores integers in the range from -2³¹ to 2³¹-1, that is approximately from -2,147,483,648 to 2,147,483,647. This is because one bit is used for the sign of the number (positive or negative), and the remaining 31 bits are for the value.

Therefore, the maximum positive value of int is about 2 billion, and attempting to store a number larger than this will cause overflow, leading to incorrect results. To store larger numbers, you should use the long type (64 bits) or classes for working with big numbers, such as BigInteger.