43 (number)

43 (forty-three) is the natural number following 42 and preceding 44.

43 is also a Wagstaff prime,[1] and a Heegner number.

[2] 43 is the fourth term of Sylvester's sequence.

[3] 43 is the largest prime which divides the order of the Janko group J4.

Amsterdam, NL: Koninklijk Wiskundig Genootschap (5) 10, No.