Largest Known Prime Number

On January 7, 2016, Dr. Curtis Cooper, a mathematician at the University of Central Missouri, discovered the 48th Mersenne prime, 2^74,207,281 - 1, a 22,338,618 digit number.
On January 25, 2013, Dr. Curtis Cooper discovered the 48th Mersenne prime, 2^57,885,161 - 1, a 17,425,170 digit number. Typed out in Times Roman 12 point font, the number would stretch more than 30 miles or fill more than six Bibles!
On April 12, 2009, the 47th known Mersenne prime, 2^42,643,801 - 1, a 12,837,064 digit number was found by Odd Magnar Strindmo from Melhus, Norway!
On September 6, 2008, the 46th known Mersenne prime, 2^37,156,667 - 1, a 11,185,272 digit number was found by Hans-Michael Elvenich in Langenfeld near Cologne, Germany!
On August 23, 2008, Edson Smith using a UCLA computer discovered the 45th known Mersenne prime, 2^43,112,609 - 1, a mammoth 12,978,189 digit number!
On September 4, 2006, Dr. Curtis Cooper and Dr. Steven Boone's CMSU team, found the largest known prime number at that time, 2^32,582,657 - 1. The prime number has 9,808,358 digits! This is the 44th Mersenne Prime Number.

On December 15, 2005, Dr. Curtis Cooper and Dr. Steven Boone, professors at Central Missouri State University, discovered the 43rd Mersenne Prime, 2^30,402,457 - 1. The prime number has 9,152,052 digits!
On February 18, 2005, Dr. Martin Nowak from Germany, found the 42nd Mersenne Prime, 2^25,964,951 - 1. The prime number has 7,816,230 digits! It took more than 50 days of calculations on Dr. Nowak's 2.4 GHz Pentium 4 computer.
On May 15, 2004, Josh Findley discovered the 41st Mersenne Prime, 2^24,036,583 - 1. The number has 7,235,733 digits. Josh's calculation took two weeks on his 2.4 GHz Pentium 4 PC.
In the December 22, 2003, issue of Newsweek magazine, Michael Shafer was quoted as saying, "I don't think I'm going to be recognized as I go down the street." He had discovered the largest known prime number up to that time, which was 6,320,430 digits long.
On November 14, 2001, Michael Cameron, a 20-year-old Canadian had discovered the previously largest known prime number to date: 2^13,466,917 - 1
On June 1, 1999, in Orlando, Florida, Nayan Hajratwala discovered the first million-digit prime number. The feat was accomplished using software written by George Woltman.
The prime number, 2^6,972,593 - 1, contains 2,098,960 digits. Nayan used a 350 MHz Pentium II IBM Aptiva computer running part-time for 111 days to prove the number prime. Running uninterupted, it would take about three weeks to test this number.

The new prime number is one of a special class of primes called Mersenne primes. Mersenne primes are of the form 2^p - 1. They are named after Marin Mersenne, the French monk born in 1588 who investigated prime numbers of the form 2^p - 1.
There are only 49 known Mersenne primes (as of December 2016).
They are listed below:

Index Number Digits in Number Year Discoverer

1 2^2-1 1 - -

2 2^3-1 1 - -

3 2^5-1 2 - -

4 2^7-1 3 - -

5 2^13-1 4 1461 -

6 2^17-1 6 1588 Cataldi

7 2^19-1 6 1588 Cataldi

8 2^31-1 10 1750 Euler

9 2^127-1 39 1876 Lucas

10 2^61-1 19 1883 Pervushin

11 2^89-1 27 1911 Powers

12 2^107-1 33 1914 Powers

13 2^521-1 157 1952 Robinson

14 2^607-1 183 1952 Robinson

15 2^1279-1 386 1952 Robinson

16 2^2203-1 664 1952 Robinson

17 2^2281-1 687 1952 Robinson

18 2^3217-1 969 1957 Riesel

19 2^4253-1 1,281 1961 Hurwitz

20 2^4423-1 1,332 1961 Hurwitz

21 2^9689-1 2,917 1963 Gillies

22 2^9941-1 2,993 1963 Gillies

23 2^11213-1 3,376 1963 Gillies

24 2^19937-1 6,002 1971 Tuckerman

25 2^21701-1 6,533 1978 Noll

26 2^23209-1 6,987 1979 Noll

27 2^44497-1 13,395 1979 Slowinski

28 2^86243-1 25,962 1982 Slowinski

29 2^132049-1 39,751 1983 Slowinski

30 2^216091-1 65,050 1985 Slowinski

31 2^110503-1 33,265 1988 Colquitt

32 2^756839-1 227,832 1992 Slowinski

33 2^859433-1 258,716 1994 Slowinski

34 2^1257787-1 378,632 1996 Slowinski

35 2^1398269-1 420,921 1996 Armengaud

36 2^2976221-1 895,932 1997 Spence

37 2^3021377-1 909,526 1998 Clarkson

38 2^6972593-1 2,098,960 1999 Hajratwala

39 2^13466917-1 4,053,946 2001 Cameron

40 2^20996011-1 6,320,430 2003 Shafer

41 2^24036583-1 7,235,733 2004 Findley

42 2^25964951-1 7,816,230 2005 Nowak

43 2^30402457-1 9,152,052 2005 Cooper/Boone

44 2^32,582,657-1 9,808,358 2006 Cooper/Boone

45 2^43,112,609-1 12,978,189 2008 Edson Smith

46 2^37,156,667-1 11,185,272 2008 Hans-Michael Elvenich

47 2^42,643,801-1 12,837,064 2009 Odd Magnar Strindmo

48 2^57,885,161-1 17,425,170 2013 Curtis Cooper

49 2^74,207,281-1 22,338,618 2016 Curtis Cooper

sources:

Dr. Michael W. Ecker
Editor and Publisher
Recreational & Educational Computing
187 Ferguson Avenue, Suite D
Shavertown, PA 18708

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