One is the loneliest number that you’ll ever do. According to the consortium of scholars known as Three Dog Night, this is a mathematical fact as certain as Jeremiah was a bullfrog. But what if Three Dog Night was wrong: What if there is a number (or many numbers) even less popular than one?
For reasons totally unrelated to classic rock, author and mathematician Alex Bellos set out to find the world’s favorite number in a massive, public vote on his website. If you have a favorite number of your own, you won’t be surprised that Bellos’ survey swiftly received more than 44,000 votes from numberphiles around the world.
Voters gave many reasons for their choices. Often, a number signified an important date, a memorable age, or simply exuded “friendliness and warmth.” Odd numbers outperformed evens, and round numbers ending in 5 or 0 proved too vague for most tastes (“When we say 100, we don’t usually mean exactly 100, we mean around 100,” Bellos says. “Why would you have something as your favorite that is so vague?”). Numbers with regular gigs in geometry were common—412 people voted for pi (3.14) and 103 voted for 1.618, the golden ratio. Even more popular were numbers with a higher purpose; 42, the proclaimed “answer to ultimate question of life, the universe and everything” from the Hitchhiker’s Guide to the Galaxy soared to 12th place.
In third place, number eight was rewarded for its lovely symmetry and associations with the Chinese character for prosperity. In second place, three took the prize for its many appearances in culture and nature (as they say, everything is better in threes). And, with nearly ten percent of the total vote, the world’s favorite number is… seven.
Shocked? Probably not. It turns out that seven’s triumph only reaffirms a human fascination that goes back thousands of years. Bellos points out that ancient Babylonian tablets were riddled with sevens, an observation future historians might make about us when reviewing footage of our Las Vegas slot machines and craps tables. There are seven dwarfs, seven samurai, seven sins, seven seas. In nature, seven days of the week, seven continents, seven planets visible in the sky with the naked eye. But all of this, Bellos suspects, is the effect, not the cause of our sevenfold obsession.
The real reason people love seven is the same reason we love James Dean, Prince, or the KFC Double-Down sandwich: Seven is a stone-cold rebel that follows no rules but its own.
“Seven is the only number among those we can count on our hands (1-10) that cannot be divided our multiplied within the group,” Bellos explains. One, two, three, four and five can each be doubled to reach two, four, six, eight, and ten. Nine is divisible by three. Seven, then, is the only number between two and ten that is neither a multiple nor a factor of the others. In this way, “lucky number seven” stands alone—and we grasp this implicitly.
“It’s unique, a loner, the outsider. And humans interpret this arithmetical property in cultural ways,” Bellos says. “By associating seven with a group of things, you kind of make them special too. The point here is that we’re always sensitive to arithmetical patterns, and this influences our behavior—even if we’re not conscious of it.” In other words, as one 16-year-old voter from New Zealand affirmed in his comments, “People don’t usually tend to pick 7, and I like to be different.”
So there you have it. If your favorite number is seven, you have a soft spot for the rebels, the individuals, the loose cannons of math and culture. And so does everyone else.
As for the real loneliest number? That’s a tie between about 800 fractions, negatives, and a few 20-digit integers that only received one vote apiece. It seems, at the end of the day, 74,656 is an even lonelier number than one.
Do you have a favorite number? Ponder it while reading these 25 short jokes every nerd will love.