Calcute: freeware calculator

e

Function e returns a close approximation of the irrational constant value of e, also known as Euler's number or Napier's constant. This value is the base of natural logarithms. The e function takes no parameter so the use of parentheses is not necessary. If parentheses are used, they must remain empty.

e
  2.71828182846


e()
  2.71828182846

Because constant e is an irrational value, it cannot be represented exactly using any finite number of digits. In order to reduce rounding errors, Calcute internally stores more fractional digits than it normally displays:

2.718281828459045235360287471352662497757247093699...