Shape of Earth is an oblate spheroidAs you can see from this…

Shape of Earth is an oblate spheroid

As you can see from this dramatic demonstration, the consequence of imparting a rotational velocity to an object is the flattening of object at the poles.

The rotational velocity of Earth is a staggering 1,674.4 km/h 
and as a result  bulges at the center by a tiny fraction, as is evident from the following image: