In the world of Python, integers are among the most fundamental and frequently used data types. Have you ever wondered what happens behind the scenes when you create a number in Python, for example: n = 9527? In some programming languages, the size of numbers can be limited by the operating system—for instance, 232 or 264. Exceeding this limit can result in an “Overflow,” but why is Python capable of handling integers of arbitrary size? And why do integers between -5 and 256 have certain special properties? In this chapter, we’ll explore these questions in detail.