1803

1803 = 3 x 601.

1803 is a semiprime that becomes a triangular number when its digits are reversed (3081) (A115741).

1803 divides 25⁶ - 1. It also divides 2⁵⁰ - 1 (A003554).

1803 is 2423 in base 9.

1803 is not a number that is the sum of a triangular number, a cube, and a positive Fibonacci number (A115177).

1803 is a non-leap year beginning and ending on a Saturday (A224994).

Source: On-Line Encyclopedia of Integer Sequences