181 is a prime number.
181 can be represented as the sum of two squares: 92 + 102 = 181.
181 is the hypotenuse of a primitive Pythagorean triple: 1812 = 192 + 1802.
181 is a centered square number.
Rusty Romeos was the 181st short film starring the Three Stooges, released October 17, 1957.
Source: Wikipedia
