Mathematically, which of the following years is NOT a perfect square year?

2106 may be just another year, while 2209, 2025 and 1936 are perfect square years. A perfect square year is simply a year that can be written as the square of a whole number. For example, 1936 = 44^2, 2025 = 45^2, 2209 = 47^2.

The sequence of perfect square years starts all the way back at 1AD, and continues at increasingly wider intervals. As the number grows larger, the gaps between successive perfect square years also expand, making each one feel even more special.

We’ve had 45 perfect square years in total leading up to 2025. The previous perfect square year was 1936, a whooping 89 years ago. The one before that was 1849, which occurred 87 years earlier. Looking ahead, the next perfect square year will be 2116, that is 46^2, marking another 91-year gap. Beyond 2116, two perfect square years are: 2209 =47^2 (93 years after 2116), and 2304 = 48^2 (another 95 years later).

As the gaps grow, it becomes even less likely for any one person to witness more than one or two perfect square years in their lifetime. If you’ve experienced both 1936 and 2025, count yourself among the lucky few who have seen two of these milestones.

These rare, logical and beautiful years are elegant markers of time, neatly woven into the fabric of history, demonstrating the predictability of numbers and how mathematical patterns play out in the real world.