Master Numbers are basically double-digit numbers consisting of two identical digits. Double digit numbers can be 11,22,33 and the series goes on. Here 11,22,33 is considered as the master number because 11 contains the digit 1 twice, the 22 is a Master Number because it consists of the number 2 twice and 33 is made up of the number 3 twice. So, it is the repetition of the numbers 1, 2, and 3 specifically that makes the 11, 22 and 33 Master Numbers.