Sumanta Sarkar, et al. give a class of rotation symmetric Boolean functions with maximum algebraic immunity, but only consider the nonlinearity of the functions and did not study other cryptographic properties. In this paper, other cryptographic properties of the class of Boolean functions are studied, such as, algebraic degree, linear structure, propagation, correlation immunity etc. The results, unfortunately, show that their other cryptographic properties are not good even though their algebraic immunity is optimum. Hence, the class of Boolean functions cannot be applied in cryptography.