How to distinguish whether a patent is an invention patent or a utility model patent from the patent number?

The public number/announcement number is sorted according to the document serial number, and they are all seven-digit numbers, preceded by the international common country code (CN), and the first digit is used to distinguish three different patents.

"1" stands for invention patent, "2" stands for utility model and "3" stands for design patent.

The last six digits indicate the serial numbers of various patent documents in that year, and the English letters marked after the serial numbers indicate the categories of various patent specifications or the legal status of the patent.