The secret life of numbers has fascinated people ever since humans learned to count. Join Marcus as he investigates where our numbers came from and where they are going, how big they can get and whether infinity is really a number. Explore the mysterious primes, the indivisible numbers. Just why did Beckham choose the number 23 shirt? And why do sunflowers have 89 petals? Find out how to try for the $1 million prize for cracking mathematics' biggest mystery.