This number is a composite.
The largest number which is divisible by its prime sum of digits (19) and reversal (91) happens to be Ramanujan's famous taxi-cab number (1729 = 123 + 13 = 103 + 93). It is the smallest number expressible as the sum of two positive cubes in two different ways.
Schiemann's first pair of isospectral lattices L+(1,7,13,19) and L-(1,7,13,19) are of determinant 1*7*13*19 = 1729. [Poo Sung]
The Hardy-Ramanujan number is equal to the average of the only known prime squares of the form n! + 1, i.e., 25, 121, and 5041. [Gudipati]