1203

1203 = 3 x 401.

1203 is a divisor of 20⁴ - 1.

1203 is the smallest number n for which the concatenation n, (n + 1), (n + 2), . . . . (n + 34) is prime (A052079).

1203 is 102303 in base 4, 14303 in base 5, and 303 in base 20. It is 717 in base 13.

1203² = 1447209 and 1203³ = 1740992427 have the same set of digits (A029797 and A045620).

Source: What's Special About This Number?