Researchers find largest prime number yet

KANSAS CITY, Mo. — Mathematicians at the University of Central Missouri have identified the largest prime number yet, but good luck remembering it.

The university said Wednesday that a group led by computer science and mathematics professor Curtis Cooper found the 17 million-digit prime number last month. It is the 48th known Mersenne prime and is the third discovered at the 11,800-student university in Warrensburg, about 50 miles east of Kansas City.

Primes are numbers such as 3, 7 and 11 that are divisible only by themselves and 1 without leaving a remainder.

Mersenne primes are named after the 17th century French mathematician who discovered them, Marin Mersenne. They’re expressed as 2P-1, or two to the power of “P” minus one. P is itself a prime number. For the new prime, P is 57,885,161.

The number was independently verified using different programs running on different hardware, according to the Great Internet Mersenne Prime Search, or GIMPS, a cooperative in which underused computing power is harnessed to perform the calculations needed to find and verify Mersenne primes.

The university, which is affiliated with the worldwide computing project, used about 1,000 campus computers in its search. Special software allows students to check email and write papers on campus computers while the machines’ excess computing capacity searches for the elusive numbers.

The school also found then-record prime numbers in 2005 and 2006. Mathematicians at UCLA broke the Missouri school’s record in 2008 with a 13 million-digit prime number.

Cooper, whose group’s latest finding is eligible for a $3,000 research award, said each subsequent prime number is tougher to find.

“Every time I find one it is incredible,” Cooper said. “I kind of consider it like climbing Mount Everest or finding a really rare diamond or landing somebody on the moon. It’s an accomplishment. It’s a scientific feat.”

Mike Breen, a spokesman for the American Mathematical Society, said the large prime numbers are exciting for mathematicians and computer scientists. He noted the latest number discovered is so enormous that is would take reams and reams of paper to print it out.

“It is great to test computers,” Breen said. “When they find a number, they have to find out, it looks like it might be a prime, but they don’t know for sure, so they have to do all kinds of tests on it. That is a good way to test how your algorithm is working, how fast your computer is. Things like that.”

Meanwhile, the hunt continues for a 100 million-digit prime number, which could fetch a $150,000 prize from the Electronic Frontier Foundation, a San Francisco-based nonprofit.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Traffic moves around parts of the roundabout at the new I-5/SR529 interchange on Tuesday, July 22, 2025 in Marysville, Washington. (Olivia Vanni / The Herald)
WSDOT delays opening of Marysville interchange, ramps

Supply chain issues caused the agency to push back opening date. The full interchange and off ramps are expected to open in October.

Stanwood pauses Flock cameras amid public records lawsuits

A public records request for Flock camera footage has raised questions about what data is exempt under state law.

A Link train passes over a parking lot south of the Lynnwood City Center Station on Monday, Aug. 12, 2024 in Lynnwood, Washington. (Olivia Vanni / The Herald)
Construction to close parking spots at Lynnwood Link station

Fifty-seven parking spots out of the nearly 1,700 on-site will be closed for about two months.

Provided photo 
Michael Olson during his interview with the Stanwood-Camano School District Board of Directors on Sept. 2.
Stanwood-Camano school board fills vacancy left by controversial member

Michael Olson hopes to help bring stability after Betsy Foster resigned in June.

Traffic moves along Bowdoin Way past Yost Park on Monday, Aug. 25, 2025 in Edmonds, Washington. (Olivia Vanni / The Herald)
A new online tool could aid in local planning to increase tree coverage

The map, created by Washington Department of Natural Resources and conservation nonprofit American Forests, illustrates tree canopy disparities across the state.

Logo for news use featuring Snohomish County, Washington. 220118
Snohomish PUD preps for more state home electrification funding

The district’s home electrification rebate program distributed over 14,000 appliances last year with Climate Commitment funds.

Logo for news use featuring the municipality of Everett in Snohomish County, Washington. 220118
One person dead in single-vehicle crash on Wednesday in Everett

One man died in a single-vehicle crash early Wednesday morning… Continue reading

Students walk outside of Everett High School on Wednesday, Sept. 17, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
SnoCo students perform well on metrics, state data shows

At many school districts across the county, more students are meeting or exceeding grade-level standards compared to the state average.

People get a tour of a new side channel built in Osprey Park on Thursday, Sept. 18, 2025 in Sultan, Washington. (Olivia Vanni / The Herald)
Snohomish PUD cuts ribbon on new Sultan River side channel

The channel created 1,900 linear feet of stream habitat, aimed to provide juvenile salmon with habitat to rest and grow.

Logo for news use featuring the municipality of Everett in Snohomish County, Washington. 220118
Auditor dismisses challenge against former Everett candidate’s registration

The finding doesn’t affect a judge’s ruling blocking Niko Battle from appearing on the November ballot.

The Seattle Children’s North Clinic at 1815 13th St. in Everett, near Providence Regional Medical Center Everett in 2018. (Seattle Children’s)
Seattle Children’s layoffs include Everett employees amid federal cuts

The company will lay off 154 employees this fall across five locations. It’s unclear how many positions in Everett will be eliminated.

Everett NewsGuild members cheer as a passing car honks in support of their strike on Monday, June 24, 2024 in Everett, Washington. (Olivia Vanni / The Herald)
Unionized Herald staff ratify first contract with company

The ratification brings an end to two years of negotations between the newspaper and the union.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.