765

765 = 3 x 3 x 5 x 17.

765 has two representations as a sum of two squares: 765 = 6² + 27² = 18² + 21².

765 = 401 + 263 + 89 + 7 + 5. Its reversal, 567, is the smallest number that is the sum of different primes using all ten digits.

765 is 1011111101 in base 2 (A006995) and 636 in base 11.

765 is the sum of eight positive fifth powers (A003353): 765 = 3⁵ + 3⁵ + 3⁵ + 2⁵ + 1⁵ + 1⁵ + 1⁵ + 1⁵.

Source: Prime Curios!