91

91 (ninety-one) is a positive integer following 90 and preceding 92. Its ordinal form is written "ninety-first" or 91st.
== Properties ==
91 is an OEIS, Sequence A002808 (accessed 2021-02-07).
91 is the 13th , and therefore the number of tiles in a double-12 set.
== In googology ==
In Greek-based number-naming systems, 91 is associated with prefix "henenneaconta-", and with prefix "unnonaginti-" in Latin systems.
==Sources==
Category:Numbers
Category:Class 1
Category:Domino-related numbers
Category:Non-powers
Category:Numbers with 1 to 2 digits
Category:Odd numbers