You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [3,5-bis[hydroxy(oxo)azaniumyl]-2,4,6-tris[[hydroxy(oxo)azaniumyl]oxy]-1,3,5-triazinan-1-yl]-hydroxy-oxoazanium by IUPAC nomenclature, provide its molecular formula.
user
C3H9N9O15+6
assistant