Odd ninth prime number, fifth factorial prime number, fourth safe prime number, fifth Sophie Germain prime number, third crowded prime number, second crowded prime number, second Smaranda-Williamson prime number. It also has no imaginary part, and the real part is a eisenstein prime in the form of 3n- 1 The smallest non-twin prime number consists of 1, and the number of 23 bits is a prime number (i.e.1,1 1,1,1/68)/.