The following characters play a special role in LaTeX and are called "special printing characters", or simply "special characters".
# $ % & ~ _ ^ \ { }
Whenever you put one of these special characters into your file, you are
doing something special. If you simply want the character to be printed
just as any other letter, include a \ in front of the character.
For example, \$ will produce $ in your output.
One exception to this rule is the \ itself because \\ has
its own special meaning. A \ is produced by typing
$\backslash$ in your file.
Also, \~ means `place a tilde accent over the following letter',
so you will probably want to use \verb instead.
In addition, you can access any character of a font once you know its
number by using the \symbol command. For example, the character
used for displaying spaces in the \verb* command has the code
decimal 32, so it can be typed as \symbol{32}.
You can also specify octal numbers with ' or hexadecimal numbers
with ", so the previous example could also be written as
\symbol{'40} or \symbol{"20}.