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), ...

Jared Duker Lichtman, 26, has proved a longstanding conjecture relating prime numbers to a broad class of “primitive” sets. To his adviser, it came as a “complete shock.” As the atoms of arithmetic, ...