New Largest Known Prime Number Has More Than 23 Million Digits

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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. 

America's Divorce Rate is Declining—and We Have Millennials to Thank for It

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iStock/Jason_Lee_Hughes

Millennials are reportedly killing off yet another cultural mainstay, but this time, it may be a good thing. According to Bloomberg, divorce rates are going down, thanks to the commitment powers of younger generations.

Between 2008 and 2016, the divorce rate in the U.S. dropped by 18 percent, according to a new analysis of data from the Census Bureau’s American Community Survey. Controlling for related factors like age (older people are less likely to get divorced than younger couples), the rate still dropped by 8 percent. By contrast, Baby Boomers have consistently divorced at higher rates than previous generations.

Many declines that Millennials are blamed for—like rates of homeownership or having kids—can actually be attributed to the dismal finances of a generation that came of age in a recession, is saddled with crushing student debt, and faces high costs of living and low wage growth. Divorces can be expensive, too. Yet several trends point to a higher likelihood of marriage stability for the Millennial generation that has nothing to do with finances. On average, Millennials are marrying later in life, and spending more time dating partners prior to marriage than earlier generations, both of which correlate with a lower chance of divorce, according to social scientists.

“The U.S. is progressing toward a system in which marriage is rarer, and more stable, than it was in the past,” author Philip Cohen writes in the paper.

Sorry, law school students, but it looks like being a divorce lawyer is going to get a little less lucrative in the future.

[h/t Bloomberg]

Tune in Tonight: Mental Floss on Jeopardy!

All that time you've spent on here is about to pay off.

Tune in tonight for Jeopardy! and you'll catch the debut of the "I Learned It From Mental Floss" category. Big bucket list moment for us.

We've been working closely with the Jeopardy! team over on Instagram, sharing amazing facts on both @jeopardy and @mental_floss. Study up!

Check your local listings for stations and show times.

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