Returns the natural logarithm of a number. Natural logarithms are based on the constant e (2.71828182845904).
Number is the positive real number for which you want the natural logarithm.
LN is the inverse of the EXP function.
LN(86) equals 4.454347
LN(2.7182818) equals 1
LN(EXP(3)) equals 3
EXP(LN(4)) equals 4