The natural exponent e, the base of the natural logarithm, is sometimes called Euler's Number. It is an infinite non-repeating decimal with a value of approximately: 2.71828182845904523536

e is very important in advanced mathematics. The exponential function y=e^x is a relatively special exponent. Its derivative is equal to itself. From this, it can be extended that e has a particularly special and important position in many theories of mathematical science.