What is the social security personal number?

18 digits. The social security personal number is 18 digits, because this number contains personal identity information and social security participation information, in which the first six digits are personal ID number, the last two digits are personal gender, the last two digits are personal birth year, the next four digits are personal participation area, and the last four digits are personal participation serial number. This coding method can ensure that each insured person has a unique personal number, which is convenient for social security institutions to manage and query.