The natural exponential number, denoted as e, is the base of the natural logarithm. It is sometimes referred to as Euler's Number and is an infinite non-repeating decimal. Its approximate value is: 2.71828182845904523536

e is highly significant in advanced mathematics. The exponential function y=e^x is a particularly special type of exponentiation where its derivative is equal to itself. As a result, e holds a unique and important position in various theoretical branches of mathematical science.