2.1.92 [ECMA-262-1999] Section 184.108.40.206, Number.prototype.toString (radix)
__If radix is null or undefined, throw a TypeError exception.__
__Let radNumber be the result of calling ToNumber with radix as the argument.__
__If radNumber is NaN, throw a TypeError exception.__
__Let radInteger be the result of calling ToInteger with radNumber as the argument.__
If radix __is not present or radInteger__ is the number 10 #or undefined#, then this number value is given as an argument to the ToString operator; the resulting string value is returned.
If radInteger #radix# is an integer from 2 to 36, but not 10, the result is a string, the choice of which is implementation-dependent.
For JScript 5.x the result string consists of a representation of this number value expressed using the radix that is the value of radInteger. Letters a-z are used for digits with values 10 through 35. The algorithm used to generate the string representation is the algorithm specified in [ECMA-262-1999] section 9.8.1 generalized for radixes other than 10.
__Otherwise throw a TypeError exception.__
The toString function is not generic; it throws a TypeError exception if its this value is not __a Number or__ a Number object. Therefore, it cannot be transferred to other kinds of objects for use as a method.