A corporate credit union is a cooperative nonprofit association whose members consist primarily of other credit unions and whose purposes are:
(a) To accumulate and prudently manage the liquidity of its member credit unions through interlending and investment services;
(b) To act as an intermediary for credit union funds between members and other corporate credit unions;
(c) To obtain liquid funds from other credit union organizations, financial intermediaries, and other sources;
(d) To foster and promote in cooperation with other state, regional, and national corporate credit unions and credit union organizations or associations the economic security, growth and development of member credit unions; and
(e) To perform such other financial services of benefit to its members which are authorized by the commissioner.