The number 1 is not considered a prime number because it has only 1 positive divisor. Some prime numbers form “twin primes,” like 11 and 13 or 17 and 19. These pairs differ by exactly two. Large prime ...

Three and five are prime numbers — that is, they are divisible only by one and by themselves. So are five and seven. And 11 and 13. And for each of these pairs of prime numbers, the difference is two.

The world belongs to the mathematicians and the physicists. We lay people may pump our minds with Discovery Channel specials, but they’re the ones who get to understand how it all really works–how the ...

One of my favorite anecdotes about prime numbers concerns Alexander Grothendieck, who was among the most brilliant mathematicians of the 20th century. According to one account, he was once asked to ...

A prime number has exactly two factors, itself and one. The first ten prime numbers are \({2}\), \({3}\), \({5}\), \({7}\), \({11}\), \({13}\), \({17}\), \({19 ...