Numerology is the belief in an occult, divine or mystical relationship between a number and one or more coinciding events.
Numerology is also the study of the numerical value, via an alphanumeric system, of the letters in words and names.
When numerology is applied to a person's name, it is a form of onomancy.
Numerology is the study of relationships between a person and his date of birth and the spelling of his name.