13 world’s hardest math problems, listed below.

• The Poincaré Conjecture

• The Prime Number Theorem

• Fermat’s Last Theorem

• The Reimann Hypothesis

• Classification of Finite Simple Groups

• Four Color Theorem

• Goldbach’s Conjecture

• Inscribed Square Problem

• Twin Prime Conjecture

• The Continuum Hypothesis

• Collatz Conjecture

• Birch and Swinnerton-Dyer conjecture

• The Kissing Number Problem