36 (number) 36 (number) 36 (thirty-six) is the natural number following 35 and preceding 37. 36 is both the square of six and a triangular number, making it a square triangular number. It is the smallest square triangular number other than one, and it is also the only triangular number other than one whose square root is also a triangular number. It is also a circular number- a square number that ends with the same integer by itself (6×6=36). It is the smallest number "n" with exactly eight solutions to the equation φ("x") = "n". Being the smallest number with exactly nine
Square root of 5 of five can be used. Despite having a denominator of only 72, it differs from the correct value by less than (approx. ). As of December 2013, its numerical value in decimal has been computed to at least ten billion digits. 1. This irrationality proof for the square root of 5 uses Fermat's method of infinite descent: 2. This irrationality proof is also a proof by contradiction: It can be expressed as the continued fraction The convergents and semiconvergents of this continued fraction are as follows (the black terms are the semiconvergents): Convergents of the continued fraction are colored red;