71 (seventy-one) is a positive integer following 70 and preceding 72. Its ordinal form is written "seventy-first" or 71st.


  • 71 is an odd prime number.
  • 71 is the largest known number whose square is one more than a factorial number[1].

In googology

In Greek-based number-naming systems, 71 is associated with prefix "henheptaconta-", and with prefix "unseptuaginti-" in Latin systems.

In group theory

It is also the largest prime to appear in the factorization of the order of a sporadic group.



  1. OEIS, Sequence A085692 (accessed 2021-02-11)
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