mine is 617
1601
i think that was the number of the hotel room where i lost my virginity
2⁸²⁵⁸⁹⁹³³ -1
still the largest (as of 02/2023)
24,861,808 digits. An incomprehensibly large number!
3
A Tri-Prime: November 5, 1955
282,589,933 − 1
That's my 2nd favorite