Leonhard Euler was born on the 15 of April in 1707 Basel, Switzerland. He was tutored by Johann Bernoulli in his early years, and had a natural gift at solving mathematics. Entering university at the age of 14 in 1720, he graduated a couple years later in 1723 with a master in philosophy. He then went on to work at the Petersburg Academy and the Berlin Academy of Science. He is known well for being the most prolific mathematical writer of all times, Euler published over 800 papers in his life. He also won the Paris Academy Prize 12 times.
He systematized mathematics by introducing symbols into math, such as e for bases, f(x) for functions, P for pie, and even S. He as well contributed to optics, mechanics, electricity, magnetism and significant contributions to the study of differential equations. Euler also did work in number theory, factoring the fifth Fermat number, showed that he was irrational, studied the three-body problem especially the moon, and proved the binomial theorem was valid for rational and exponent. One of the most famous introductions was the Gamma function for multi-factorials from Euler in 1729.