1535

1535 = 5 x 307.

1535 is 113333 in base 4, 2777 in base 8, and 555 in base 17.

1535 is a Thabit (or 321) number, having the form 3 x 2ⁿ - 1 for n = 9.

The sum of the digits of 1535² (2,356,225) and the product of its digits are both squares: 2 + 3 + 5 + 6 + 2 + 2 + 5 = 25 = 5² and 2 x 3 x 5 x 6 x 2 x 2 x 5 = 3600 = 60².

NGC 1535 is a nebula in the constellation Eridanus.

Source: On-Line Encyclopedia of Integer Sequences