The Hermitian conjugate of a complex number, such as 5+6i, is essentially its complex conjugate, which is 5-6i. The term "Hermitian conjugate" is primarily associated with matrices and refers to the conjugate transpose of a matrix with complex entries. When considering a complex number as a 1x1 matrix, its Hermitian conjugate aligns with its complex conjugate. In mathematical terms, the Hermitian conjugate of an operator is defined through the relationship <x,Ay> = <A*x,y>, highlighting its role as an adjoint. This concept is particularly significant in quantum mechanics, especially for infinite-dimensional operators.