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
Fast inverse square root The calculation of is based on the identity Using the approximation of the logarithm above, applied to both and , the above equation gives: Thus, an approximation of is: which is written in the code as The first term above is the magic number from which it can be inferred that . The second term, , is calculated by shifting the bits of one position to the right. With as the inverse square root, . The approximation yielded by the earlier steps can be refined by using a root-finding method, a method that finds the zero of a function. The