People hear may (or may not) know or care that the number 2025 has special properties, apart from being announced as a Jubilee year.
2025 is the square of 45, which is a triangular number. This means that 2025 is both the sum of the first nine cubes, and the sum adding the numbers 1 through 9, then squaring that.
That is:
1^3 + 2^3 + 3^3 + … 8^3 + 9^3 = 2025
(1+2+3+ … +8+9)^2 = 2025
This identity is sometimes called Nicomachus’s theorem, after Nicomachus of Gerasa (c. 60 – c. 120 CE).
You don’t care, of course. This last happened in 1296. It won’t happen again for a thousand years. But if you did, Nichomachus’ proof that the sum of the cubes equals the square of the sum is given below.