2025 FACTS
🟦 first square number since 1936, last until 2116
🟦 first product of two two-digit squares since 1764, last until 2401
🟦 product of two different square pairs: 81 x 25 and 225 x 9. (So was 1764.)
🟦 only two prime factors: 3 and 5. The last year to consist of just 3s & 5s was 1875.
🟦 first square number since 1936, last until 2116
🟦 first product of two two-digit squares since 1764, last until 2401
🟦 product of two different square pairs: 81 x 25 and 225 x 9. (So was 1764.)
🟦 only two prime factors: 3 and 5. The last year to consist of just 3s & 5s was 1875.
Comments
🟦 2025=25x81=9x225 {25=5x5 & 81=9x9; 9=3x3 & 225=15x15}
1764=1x1764 {1x1=1 & 42x42=1764}
🟦 1764=1x1764=36x49 [1x1=1 & 42x42=1764; 6x6=36 & 7x7=49}
🟦 2025=3x3x3x3x5x5 1875=3x5x5x5x5