16 (number) 0 to 15 in each column. Sixteen is an even number and a square number. Sixteen is the fourth power of two. Sixteen is the only integer that equals "m" and "n", for some unequal integers "m" and "n" ("m" = 4, "n" = 2, or vice versa). It has this property because 2 = 2 × 2. It is also equal to 2 (see tetration). 16 is the base of the hexadecimal number system, which is used extensively in computer science. In Spanish and Portuguese, 16 is the first compound number (Spanish: "dieciséis", European Portuguese: "dezasseis", Brazilian Portuguese: "dezesseis");
Complex-base system Complex-base system In arithmetic, a complex-base system is a positional numeral system whose radix is an imaginary (proposed by Donald Knuth in 1955) or complex number (proposed by S. Khmelnik in 1964 and Walter F. Penney in 1965). Let formula_1 be an integral domain formula_2, and formula_3 the (Archimedean) absolute value on it. A number formula_4 in a positional number system is represented as an expansion where The cardinality formula_6 is called the "level of decomposition". A positional number system or coding system is a pair with radix formula_8 and set of digits formula_9, and we write the standard set