Number enthusiasts may be looking to the new year with a touch of melancholy. Another perfect square like 2025 (45 2 = 2,025) won’t occur again until 2116 (46 2 = 2,116). The year 2027 will be a prime ...

Is 170,141,183,460,469,231,731,687,303,715,884,105,727 prime? Before you ask the Internet for an answer, can you consider how you might answer that question without a ...