819

819 = 3² x 7 x 13.

819 is 1100110011 in base 2 (binary) and 333 in base 16.

819 is a square pyramidal number.

819 is the largest three-digit number whose square (670761) and cube (549353259) use different digits.

819 is the smallest number such that it and its successor (820) are both the product of two primes and the square of a prime: 820 = 2² x 5 x 41.

In 1944, René Barthélemy developed an 819-line television standard.

Source: Number Gossip