If you've got the time, we've got the riddle. And it's time for a riddle about time: How many numbers are on a clock? It begins with the simplest of questions that, nevertheless, has no simple answer.

A prime number is a number that is only divisible by one and itself, which is essentially saying that it has no divisor. That takes half of all possible numbers off the table right away (the evens), ...

In the early 1970s mathematician Donald Knuth spent a sabbatical with his wife in Norway. The time was meant to be spent relaxing. Yet one night he woke up his partner in a state of agitation. He ...

What is the most bizarre real number that you can imagine? Probably many people think of an irrational number such as pi (π) or Euler’s number. And indeed, such values can be considered “wild.” After ...

For 50 years, mathematicians have believed that the total number of real numbers is unknowable. A new proof suggests otherwise. Click to tell Google to prioritize Quanta and see more of the best ...