6661

This number is a prime.

The smallest beastly prime is also an invertible prime (1999).

The sum of cube of factorial of digits of the smallest beastly prime (6!^3 + 6!^3 + 6!^3 + 1!^3) yields an emirp. [Bajpai]

The smallest beastly prime is also "lucky." [Gaydos]

The first 4-digit beastly invertible prime found in the first ten thousand invertible digits (in order of their occurrence) in decimal expansion of π. [Bajpai]

6!+6!+6!+1! = 2161 (which is prime) = 6*6*6*10 + 1, another beastly expression. [Worrom]

The hypotenuse of a right triangle with legs of 1620 and 6461. [Gaydos]