Euler's constant, sometimes called gamma or the Euler-Mascheroni constant, has the mathematical value of .577215664901532860606512090082...(like pi, this constant is an unresolvably long number).
Euler's constant (gamma) is defined as the limit of the expression (1 + 1/2 + 1/3 + 1/4 + ... + 1/ n ) - ln ( n ), as n approaches infinity . The abbreviation ln stands for natural logarithm , also called the base- e logarithm. The value of Euler's constant has been calculated to more than 1,000,000 decimal places, and is often approximated to 0.577216.
Also see the Table of Physical Constants .