33188 decimal = 100644           octal  (first printf)
07777 octal   = 0000111111111111 binary (mask)-|
                                               +- & (bitwise AND)
33188 decimal = 1000000110100100 binary (mode)-|
0644  octal   = 0000000110100100 binary (printf after mask)
                ^^^^
                  |
                  + - file type masked out