New Largest Known Prime Number Has More Than 23 Million Digits

iStock
iStock

Prime numbers come in all sizes: They go down to single digits and grow infinitely larger. But calculating the exact quantity of the largest prime numbers in existence takes serious time and effort. Now, thanks to help from a volunteer and his computer, the Great Internet Mersenne Prime Search (GIMPS) has identified the newest largest prime number we know of.

The prime number has 23,249,425 digits, surpassing the previous record holder by 1 million digits. It can be written as 277,232,917-1 or M77232917. Like other prime numbers, the quantity can only be divided by one and itself. But unlike some smaller primes, this one joins a special category called Mersenne primes.

Mersenne primes are found by calculating numbers to the second power and subtracting the value of one from the total. Only 50 prime numbers have been found this way, and a lot of computing power is required to uncover them.

Since 1996, GIMPS has been crowdsourcing computers to discover larger and larger prime numbers. Anyone can download their program and dedicate their unused processing power to churning out algorithms in search of the next record breaker. Volunteers whose computers successfully identify a new prime number are eligible for a cash reward of up to $3000.

The most recent winner was Jonathon Pace, a 51-year-old electrical engineer from Tennessee. His computer calculated the number M77232917 on December 26, and its prime status was independently verified by four separate computers.

GIMPS is constantly outdoing itself, with the previous largest prime announced just two years ago. If you'd like to join the effort, their prime-hunting software is free to download. But don't expect instant results: Pace was volunteering with GIMPS for 14 years before his altruism paid off. 

The 10 Best Memorial Day 2020 Sales

iRobot,GoWise,Funko via Wayfair, Entertainment Earth
iRobot,GoWise,Funko via Wayfair, Entertainment Earth

The Memorial Day sales have started early this year, and it's easy to find yourself drowning in offers for cheap mattresses, appliances, shoes, and grills. To help you cut through the noise and focus on the best deals around, we threw together some of our favorite Memorial Day sales going on right now. Take a look below.

1. Leesa

A Leesa Hybrid mattress.
A Leesa Hybrid mattress.
Leesa

Through May 31, you can save up to $400 on every mattress model Leesa has to offer, from the value-minded Studio by Leesa design to the premium Leesa Legend, which touts a combination of memory foam and micro-coil springs to keep you comfortable in any position you sleep in.

Find it: Leesa

2. Sur La Table

This one is labeled as simply a “summer sale,” but the deals are good only through Memorial Day, so you should get to it quickly. This sale takes up to 20 percent off outdoor grilling and dining essentials, like cast-iron shrimp pans ($32), a stainless steel burger-grilling basket ($16), and, of course, your choice of barbeque sauce to go along with it.

Find it: Sur la Table

3. Wayfair

KitchenAid Stand Mixer on Sale on Wayfair.
Wayfair/KitchenAid

Wayfair is cutting prices on all manner of appliances until May 28. Though you can pretty much find any home appliance imaginable at a low price, the sale is highlighted by $130 off a KitchenAid stand mixer and 62 percent off this eight-in-one GoWise air fryer.

And that’s only part of the brand’s multiple Memorial Day sales, which you can browse here. They’re also taking up to 40 percent off Samsung refrigerators and washing machines, up to 65 percent off living room furniture, and up to 60 percent off mattresses.

Find it: Wayfair

4. Blue Apron

If you sign up for a Blue Apron subscription before May 26, you’ll save $20 on each of your first three box deliveries, totaling $60 in savings. 

Find it: Blue Apron

5. The PBS Store

Score 20 percent off sitewide at Shop.PBS.org when you use the promo code TAKE20. This slashes prices on everything from documentaries like Ken Burns’s The Roosevelt: An Intimate History ($48) and The Civil War ($64) to a Pride & Prejudice tote bag ($27) and this precious heat-changing King Henry VIII mug ($11) that reveals the fates of his many wives when you pour your morning coffee.

Find it: The PBS Store

6. Amazon

eufy robot vacuum.
Amazon/eufy

While Amazon doesn’t have an official Memorial Day sale, the ecommerce giant still has plenty of ever-changing deals to pick from. Right now, you can take $100 off this outdoor grill from Weber, $70 off a eufy robot vacuum, and 22 percent off the ASUS gaming laptop. For more deals, just go to Amazon and have a look around.

7. Backcountry

You can save up to 50 percent on tents, hiking packs, outdoor wear, and more from brands like Patagonia, Marmot, and others during Backcountry's Memorial Day sale.

Find it: Backcountry

8. Entertainment Earth

Funko Pops on Sale on Entertainment Earth.
Entertainment Earth/Funko

From now until June 2, Entertainment Earth is having a buy one, get one half off sale on select Funko Pops. This includes stalwarts like the Star Wars and Batman lines, and more recent additions like the Schitt's Creek Funkos and the pre-orders for the upcoming X-Men movie line.

Find it: Entertainment Earth

9. Moosejaw

With the promo code SUNSCREEN, you can take 20 percent off one full-price item at Moosejaw, along with finding up to 30 percent off select items during the outdoor brand's summer sale. These deals include casual clothing, outdoor wear, trail sneakers, and more. 

Find it: Moosejaw

10. Osprey

Through May 25, you can save 25 percent on select summer items, and 40 percent off products from last season. This can include anything from hiking packs and luggage to outdoorsy socks and hats. So if you're planning on getting acquainted with the great outdoors this summer, now you can do it on the cheap.

Find it: Osprey

At Mental Floss, we only write about the products we love and want to share with our readers, so all products are chosen independently by our editors. Mental Floss has affiliate relationships with certain retailers and may receive a percentage of any sale made from the links on this page. Prices and availability are accurate as of the time of publication.

Mental Floss Is Up for a Webby Award—Here’s How to Help Us Win!

This woman doesn't work for us, but she sure is happy about our Webby Award nomination!
This woman doesn't work for us, but she sure is happy about our Webby Award nomination!
Andrea Piacquadio, Pexels

The writers, editors, videographers, tech whizzes, and everybody else on the Mental Floss team began today like any other: guzzling coffee by the gallon, eager to deliver a blend of zany and informative content straight to the brains of our readers. By mid-morning, our makeshift home offices were buzzing with a heightened, electric energy—because we’d just been nominated for a Webby Award, and we’re really excited about it.

The International Academy of Digital Arts & Sciences (IADAS) has included Mental Floss in the “Weird” general website category, which highlights sites “that reflect a fresh perspective in thought and action strong enough to start a revolution, change a behavior pattern, or advance old thinking lodged in bad habits, or that are just plain weird.”

Basically, there are two winners for each category. The Webby Award is chosen by IADAS members like Arianna Huffington, Monica Lewinsky, Darren Aronofsky, and representatives from just about every other industry out there. The IADAS has honored Mental Floss with two Webby Awards in the past; the website won one in 2013 for best cultural blog, and John Green nabbed another in 2015 for being the much-beloved host of our YouTube channel.

The Webby People’s Voice Award, on the other hand, is voted on by the public. So if you think Mental Floss embodies any (or all) of the aforementioned criteria for Best Weird General Website, you can help us win a People’s Voice Award by voting here. We’re up against some steep competition, including Brand Name Pencils, the world’s largest collection of vintage brand-name pencils, and Amazon Dating, a completely fake dating site modeled after Amazon’s homepage.

Voting is open through Thursday, May 7, and the winners will be announced on Tuesday, May 19, before a special online celebration called “Webbys From Home” that’ll showcase some of the internet’s best content from the past year.

You can explore all the nominees and vote in other categories here.