">
181 is a Centered Square Number.
181 is a Centered Pentagonal Number.
181 is a Centered 12-gonal Number.
181 is a Centered 18-gonal Number.
181 is a Centered 30-gonal Number.
For Further Reading please use the Amazon Book links on the top left and right of this page. Thankyou. Please copy and paste this code: <a href=" "> </a>