Numerology is defined by Merriam-Webster as "the study of the occult significance of numbers." According to Wikipedia, which goes into more depth on the subject, numerology is "any of many systems, traditions or beliefs in a mystical or esoteric relationship between numbers and physical objects or living things."
By any definition, numerology has been part of societal life for centuries, dating back to ancient Greeks and early mathematicians, such as Pythagoras, who used the concepts behind the numbers as they believed it was very important. In China, the belief in the power of numbers is very strong, with each number meaning something, especially in the areas of luck and prosperity. Today, numerology is most often manifested in the areas of fortune-telling and astrology.
Numerology may have even tangentially been used in the critically acclaimed 2007 movie by the Coen Brothers, No Country For Old Men. One review even speculated that "there is probably a film studies thesis being written now about the use of reflection or numerology in this film."