the natural exponent e is the base of the natural logarithm, sometimes also 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 index. its derivative function is equal to itself. by extension, among many theories in mathematical science, e is particularly special and important. important position.