The17th digit of the ID number represents the gender of the holder. If it is odd, it is male, and even, it is female. The age can be inferred from 7- 10, because 7- 10 represents the birth year of the holder; The 1-6 digits of the ID card represent the holder's domicile.

Format of ID number

1. Number structure

Citizenship number is a characteristic combination code, which consists of 17 bit ontology code and check code. The order from left to right is: six-digit address code, eight-digit date of birth code, three-digit serial code and one-digit check code.

2. Address code

The administrative division code of the county (city, flag, district) where the permanent residence of the coding object is located shall be implemented according to GB/T2260.

3. Date of birth code

Indicates the year, month and day when the coded object was born, which is implemented according to GB/T7408. There is no separator between the year, month and day codes.

4. Sequence code

It refers to the serial number of people born in the same year, month and day in the area identified by the same address code. Odd numbers of serial numbers are assigned to men and even numbers to women.

5. Check code

According to the previous 17 bit code, the check code is calculated according to the check code of ISO 7064: 1983. MOD 1 1-2。

The order from left to right is: six-digit address code, eight-digit date of birth code, three-digit serial code and one-digit check code. Resident identity card is an effective national legal certificate to prove the personal identity of citizens.