SUMPRODUCT(...)

Category: Math and trigonometry

Returns the sum of the products of corresponding array components

SUMPRODUCT(array1, [array2], [array3], ...)

Category: Math and trigonometry

Returns the remainder from division

MOD(number, divisor)

Category: Lookup and reference

Returns the row number of a reference

ROW([reference])

Category: Lookup and reference

Returns a reference indicated by a text value

INDIRECT(ref_text, [a1])

0

The formula uses the fact that for a perfectly divisible number, the numerator must be zero.