Math.LOG10E
syntax: 
Math.LOG10E 
description: 
The number value for the base 10 logarithm of e, the base of the natural logarithms. This value is represented internally as approximately 0.4342944819032518. The value of Math.LOG10E is approximately the reciprocal of the value of Math.LN10

example: 
var n = Math.LOG10E 