73 (number)

72 73 74
Cardinalseventy-three
Ordinal73rd
(seventy-third)
Factorizationprime
Prime21st
Divisors1, 73
Greek numeralΟΓ´
Roman numeralLXXIII, lxxiii
Binary10010012
Ternary22013
Senary2016
Octal1118
Duodecimal6112
Hexadecimal4916

73 (seventy-three) is the natural number following 72 and preceding 74. In English, it is the smallest natural number with twelve letters in its spelled out name.

It is the 21st prime number and the fourth star number. It is also the eighth twin prime, with 71.