(1) All public officers and bodies of this state;
(2) All political subdivisions of this state;
(3) All insurance companies and associations, and other persons carrying on an insurance business;
(4) All banks, bankers, trust companies, savings banks, and savings associations, including savings and loan associations, building and loan associations, investment companies, and other persons carrying on a banking business;
(5) All administrators, guardians, executors, trustees, and other fiduciaries; and
(6) All other persons whatsoever who are authorized to invest in bonds or other obligations of the state