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 a matrix linear map is completely positive if and only if it is of the form where "k" ≤ "nm". Let {"E"} ⊂ C be the "n" elementary matrix units. The positive matrix is called the "Choi matrix" of Φ. The Kraus operators correspond to the, not necessarily square, square roots of "M": For any square root "B" of "M", one can obtain a family of Kraus operators "V" by undoing the Vec operation to each column "b" of "B". Thus all sets of Kraus operators are related by partial isometries. In quantum physics, a density matrix for an "n"-level quantum system