An object representation of numeric data and placeholder for numeric constants.
function Number( [value : Number] ) 
Arguments
 value

Required. The numeric value of the Number object being created.
Remarks
The Number object is a wrapper for numeric data. The primary purposes for the Number object are to collect its properties into one object and to allow numbers to be converted into strings via the toString method. The Number object is similar to the Number data type. However, they have different properties and methods.
Note 

You rarely need to construct a Number object explicitly. The Number data type should be used in most circumstances. Since the Number object interoperates with the Number data type, all Number object methods and properties are available to a variable of type Number. For more information, see Number Data Type. 
The Number object is stores numeric data as an eightbyte, doubleprecision, floatingpoint number. It represents a doubleprecision 64bit IEEE 754 value. The Number object can represent numbers in the range negative 1.79769313486231570E+308 through positive 1.79769313486231570E+308, inclusive. The smallest number that can be represented is 4.94065645841247E324. The Number object can also represent NaN (Not a Number), positive and negative infinity, and positive and negative zero.
The data type of a Number object is Object, not Number.