IdentityMatrix[n] gives the n*n identity matrix.
IntegerExponent[n, b] gives the highest power of b that divides n.
KroneckerDelta[n_1, n_2, ...] gives the Kronecker delta \[Delta] Subscript[n, 1] Subscript[n, 2] ..., equal to 1 if all the n_i are equal, and 0 otherwise.
Lighter
(Built-in Mathematica Symbol) Lighter[color] represents a lighter version of the specified color. Lighter[color, f] represents a version of the specified color lightened by a fraction f. Lighter[image, ...
NumberFieldFundamentalUnits[a] gives a list of fundamental units for the field \[DoubleStruckCapitalQ][a] generated by the algebraic number a.
PrimePowerQ[expr] yields True if expr is a power of a prime number, and yields False otherwise.
SignTest[data] tests whether the median of data is zero. SignTest[{data_1, data_2}] tests whether the median of data_1\[Dash] data_2 is zero.SignTest[dspec, \[Mu] 0] tests a ...
SquareFreeQ[expr] gives True if expr is a square-free polynomial or number, and False otherwise.SquareFreeQ[expr, vars] gives True if expr is square free with respect to the ...
TranslationTransform[v] gives a TransformationFunction that represents translation of points by a vector v.
VertexColors is an option for graphics primitives which specifies the colors to assign to vertices.