320

320 = 2⁶ x 5.

320 has a representation as the sum of two squares: 8² + 16² = 320.

320 is the maximum determinant of a 10 x 10 matrix of 0s and 1s.

320 is 500 in base 8.

There are 320 rods in a mile; 320 is also the number of fluid ounces in a peck.

Source: Number Gossip