What is the first digit of Shaanxi social security unit number?

Social security number is also called social security number, which is mainly divided into individuals and units. The company's social security number is the social security registration number established by the work unit, which is used to pay social security for employees, and make some inquiries, declarations and statistics according to this social security number. Personal social security number is the login number of the individual or the company that pays for it, and it is also the basis for enjoying the treatment in the future.