What does the personal social security registration number mean?

Social security personal number is also the social security "computer number" that we need to use when querying social security, which is usually 7 or 9 digits. A "personal number" automatically generated after I register for social security represents your personal information, through which you can find your social security card number and so on, and almost all social security businesses are queried through this number.

The social insurance registration certificate number shall be marked with the abbreviations of provinces, autonomous regions and municipalities directly under the Central Government, and shall be coded uniformly within the scope of provinces, autonomous regions and municipalities directly under the Central Government. The social insurance agencies of provinces, autonomous regions and municipalities directly under the Central Government shall report the area codes of the provinces, autonomous regions and municipalities directly under the Central Government to the Ministry of Labor and Social Security for the record.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.