43 (number)
43 is the natural number following 42 and preceding 44.
Mathematics
43 is a prime number, and a twin prime of 41. 43 is the smallest prime that is not a Chen prime. 43 is also a Wagstaff prime, and a Heegner number. 43 is the fourth term of Sylvester's sequence.43 is the largest prime which divides the order of the Janko group J4.
Dutch mathematician Hendrik Lenstra wrote a mathematical research paper discussing the properties of the number, titled ''Ode to the number 43.''