Biggest prime number

Its size is amazing! About 13 million characters long, this 45th Mersenne prime number makes the number of atoms in a known universe an insignificant value, with their “total 80-digit figure”. The prime number form of Mersenne is beautiful and smart: 2 ⁿ -1, where n is a prime number. The sequence of Mersenne numbers begins as follows: 1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, ... (sequence A000225 in OEIS).

Mersenne primes are the largest primes known to science. The previous world record belonged to the number 232582657-1, having 9.808.358 digits.
')
The last, 44th number was found two years ago, and the current one - at the beginning of autumn . There is no hope of writing this number: 2 ^43,112,609 -1 would take many kilometers in length. I think you can imagine what 13 mb of numbers is.

via Science News