A standard piano has 52 white keys and 36 black for a total of 88 keys. The white keys are referred to as the natural keys, and the black keys are commonly called accidentals or sharps and flats.
While the piano has only 88 keys, it contains 230 strings with each string having 165 pounds of tension. As far as the construction of the piano, the first note to the far left is an A, and middle C is not actually the center of the keyboard. The middle of a concert piano is actually the space between the E and the F that lies above middle C.