what is the highest numbers on number line Share with your friends Share 2 Aprajita answered this infinity is the highest number on a number line as there are infinite numbers and a number line can represent very great numbers even higher than trillions and zillions.Hope this cleared your doubts. 2 View Full Answer Subhashis Dash answered this jnmfgh -3 H L Bose answered this infinity is the highest no, on number line 0 Shet Prajwal P answered this Infinity 0