510 starts with Chengdu City, Sichuan Province, and 511 means Neijiang, Leshan, Emei, Nanchong, Langzhong, Meishan, Guang'an, Wanyuan, and Bazhong in Sichuan Province.
The first two digits of the Sichuan Chengdu ID card (number 65438 0-4) are 5101; the administrative code of Chengdu is 510100, and the first six digits of the ID card are between 5100-510199, both of which are in Chengdu, Sichuan Province The ID card number means that the city represented is Chengdu.
The first two digits of the ID card number represent the provincial unit (just because the third digit is mostly 0, so people are used to referring to it by province), and the third digit actually represents the unit directly with the fourth digit. For prefecture-level units, and there are many cities (states) in Sichuan, the third position is all 0, which is not enough.
What do each number of the ID number mean?
The address code (the first six digits of the ID number) represents the administrative division code of the county (city, town, district) where the coding object’s permanent residence is located. 1-2 province, autonomous region, and municipality codes; 3-4 prefecture-level city, province, and autonomous prefecture codes; 5-6-digit county, county-level city, and district codes.
The date of birth code (the seventh to fourteenth digits of the ID number) indicates the year, month, and day of the birth of the coding object.
The sequence code (the 15th to 17th digits of the ID number) is a sequence number assigned to people born in the same year, month, and day in the area identified by the address code. Among them, the seventeenth odd number is given to men and the even number is given to women.
The check code (the last digit of the ID number) is calculated based on the previous 17-digit code and the ISO 7064: 1983 check code. MOD 11-2.