>>13969319 (PB)

hexadecimal. People use base 10 (0-9) in day to day life. It is convenient in computers to use base 16 (0-F).

Each digit represents 4 bits.

0000 = 0

0001 = 1

0010 = 2

…

1001 = 9

1010 = A (10 decimal)

…

1111 = F

8 bits can represent 0-255. In hexadecimal, FF = 255 or 1111 1111 (all 8 bits set to 1).