The Baron wrote:47?
Forty-seven is the 15th prime number, a safe prime, the 13th supersingular prime, and the 6th Lucas prime. 47 is a highly cototient number. It is an Eisenstein prime with no imaginary part and real part of the form 3n − 1.
It is also a Keith number, because it recurs in a Fibonacci-like sequence started from its base 10 digits: 4, 7, 11, 18, 29, 47...
47 is a strictly non-palindromic number.
Its representation in binary being 00101111, 47 is a prime Thabit number, and as such is related to the pair of amicable numbers {17296, 18416}.
the number forty-seven occurs in nature with noticeably higher frequency than other natural numbers.