Euler's number e is approximately 2.71828182845904523536, one of the most important mathematical constants alongside π and i.
The significance of e lies in its unique calculus properties: it's the only number where the derivative of e^x equals e^x itself.
This property makes e the natural choice for modeling continuous growth and decay processes in science and engineering.
Understanding e and its related functions provides foundation for advanced mathematical concepts and real-world applications.