"Here’s a number to savor: 243,112,609-1.
Its size is mind-boggling. With nearly 13 million digits, it makes the number of atoms in the known universe seem negligible, a mere 80 digits.
And its form is tidy and lovely: 2n-1.
But its true beauty is far grander: It is a prime number. Indeed, it is the largest prime number ever found."