43 (number)

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

← 42 43 44 →
← 40 41 42 43 44 45 46 47 48 49 → List of numbers Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	forty-three
Ordinal	43rd (forty-third)
Factorization	prime
Prime	14th
Divisors	1, 43
Greek numeral	ΜΓ´
Roman numeral	XLIII, xliii
Binary	1010112
Ternary	11213
Senary	1116
Octal	538
Duodecimal	3712
Hexadecimal	2B16

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,^[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.

Dutch mathematician Hendrik Lenstra wrote a mathematical research paper discussing the properties of the number, titled Ode to the number 43.

The Sri Yantra, with nine interlocking triangles that collectively form 43 smaller triangles