Who is the world's greatest genius?

Well, it depends as this is a context sensitive question as if you're referring to an Intellectual Quotient test than Ms. Marilyn Vos Savant has the highest recorded IQ in history at 230. Meanwhile, if you're referring to the greatest genius of all time was allegedly Albert Einstein whose IQ was quoted at 160, though he never took any IQ tests. And, if you're referring to the greatest engineering genius it might well have been Nikola Tesla the founder of Alternating Current electricity and many other prestigious devices whose work elevated mankind into the 21st century.