What starts with a P, ends with an E, and has thousands of letters?

What loses its head in the morning and gets it back at night?

What gets bigger the more you take away from it?

What is black when clean and white when dirty?

What kind of dog never barks?

I am an odd number. Take away one letter and I become even. What number am I?

Forward I am heavy, but backward I am not. What am I?