The DHT11 is a digital component with its own digital communication protocol.
Analog pins can be used for either analog input or digital input and output.
You can use a digital device like the DHT11 on any pin, whether it is labelled analog or digital (except on a couple of boards which have a few analog-only pins).
You cannot do what you are trying to do. There is no direct correspondence between some number of bits and a decimal digit.
With hexadecimal, every 4 bits corresponds to exactly 1 hex digit. That is why hex is used for computers.
One hex digit represents exactly 4 bits. Every time you add another hex digit, you add 4 bits.
Two hex digits corresponds to ...