Why 2025 is a rare 'perfect square year'

(NEXSTAR) – Regardless of how 2025 turns out, it's no ordinary year.

The year 2025 is a "perfect square year" because it's the product of a number multiplied by itself – 45x45=2025, a phenomenon that hasn't happened for decades.

The last time it occurred in 1936 (44x44), President Franklin D. Roosevelt was in office and America was slogging through the Great Depression. It was also the birth year of Mary Tyler Moore and John Madden.

The year's square properties are not the only reason that 2025 has some mathematicians excited.

“We know that it’s 45x45, but what’s cool about the number 45 is that 45 is equal to 1+2+3+4+5+6+7+8+9,” University of Waterloo Computer Science Professor Craig Kaplan told CTV News. “If you add up all the numbers from 1 to 9, you get 45. 45 is sometimes called a triangular number, or a pyramid number.”

The next perfect square year won't arrive until 2116.