The HEX function

In the following query, the HEX function returns the hexadecimal format of two columns in the customer table, as the result shows.
Figure 1: Query
SELECT HEX (customer_num) hexnum, HEX (zipcode) hexzip 
   FROM customer;
Figure 2: Query result
hexnum     hexzip

0x00000065 0x00016F86
0x00000066 0x00016FA5
0x00000067 0x0001705F
0x00000068 0x00016F4A
0x00000069 0x00016F46
0x0000006A 0x00016F6F
⋮