The solitude of Prime numbers (La solitudine dei numeri primi) (№ 90834)

Prime numbers are divisible only by one and themselves. They're special numbers, suspicious and solitary. Some Prime numbers are even more special: they are called "twin primes", a pair of Prime numbers that only differ by 2, like 11 and 13 or 17 and 19. But twin primes never touch because they're always separated by an even number.