# Curtis Cooper (mathematician)

Curtis Cooper
Nationality American
Alma mater Iowa State
Scientific career
Fields Mathematics, Computer Science
Institutions Central Missouri

Curtis Niles Cooper is an American mathematician. He currently is a professor at the University of Central Missouri, in the Department of Mathematics and Computer Science.

## GIMPS

Using software from the GIMPS project, Cooper and Steven Boone found the 43rd known Mersenne prime on their 700 PC cluster on December 15, 2005. The prime, 230,402,457 − 1, is 9,152,052 digits long and is the ninth Mersenne prime for GIMPS.[1]

Cooper and Boone became the first GIMPS contributors to find two primes when they also found the 44th known Mersenne prime, 232,582,657 − 1 (or M32,582,657), which has 9,808,358 digits . This prime was discovered on September 4, 2006 using a PC cluster of over 850 machines. This is the tenth Mersenne prime for GIMPS.[2]

On January 25, 2013, Cooper found his third Mersenne prime of 257,885,161 − 1.[3]

On September 17, 2015 (but not actually noticed until January 7, 2016), Cooper discovered yet another Mersenne prime, 274,207,281 - 1, which was the largest known prime number at 22,338,618 decimal digits.[4]

## Areas of research

Cooper's own work has mainly been in elementary number theory, especially work related to digital representations of numbers. He collaborated extensively with Robert E. Kennedy. They have worked with Niven numbers, among other results, showing that no 21 consecutive integers can all be Niven numbers,[5] and introduced the notion of tau numbers, numbers whose total number of divisors are itself a divisor of the number.[6] Independent of Kennedy, Cooper has also done work about generalizations of geometric series, and their application to probability.[7]

Cooper is also the editor of the publication Fibonacci Quarterly.

## Notes

1. ^ "Project Discovers New Largest Known Prime Number, 230,402,457-1", Great Internet Mersenne Prime Search, retrieved 2006-11-26.
2. ^ "Project Discovers Largest Known Prime Number, 232,582,657-1", Great Internet Mersenne Prime Search, retrieved 2006-11-26.
3. ^
4. ^ "Largest Known Prime, 49th Known Mersenne Prime Found!!". Great Internet Mersenne Prime Search. Retrieved 2016-01-19.
5. ^ Cooper, Curtis; Kennedy, Robert E. (1993), "On Consecutive Niven Numbers" (PDF), Fibonacci Quarterly, 31 (2): 146–151
6. ^ ———; Kennedy, Robert E. (1990), "Tau numbers, natural density, and Hardy and Wright's theorem 437", International Journal of Mathematics and Mathematical Sciences, 13 (2): 383–386, doi:10.1155/S0161171290000576.
7. ^ ——— (1986), "Geometric Series and a Probability Problem", American Mathematical Monthly, Mathematical Association of America, 93 (2): 126–127, doi:10.2307/2322711, JSTOR 2322711.