16 (Number)

16 is a natural number that follows 15 and precedes 17. It is an even number, meaning it is divisible by two with no remainder. It is written as 16 in the decimal system, XVI in Roman numerals, and 10000 in the binary system.

The most notable property of 16 is that it is the fourth power of 2 (2×2×2×2 = 16) and also the square of 4 (4² = 16). Its divisors are 1, 2, 4, 8, and 16—all powers of 2. The sum of its proper divisors (1+2+4+8 = 15) is less than 16, so 16 is classified among deficient numbers.

Mathematical Properties

16 is a composite number and not prime; its prime factorization is 2⁴. It is a perfect square whose square root is 4. It is also notable for the property that 2⁴ = 4² = 16, making it a number expressible in two different ways as a power. Additionally, 16 is the total number of basic colors that can be represented by a single 4-bit computer value, since 2⁴ = 16.

Hexadecimal System

16 is the base of the hexadecimal numbering system, which is widely used in computer science. That system uses the digits 0–9 and the letters A–F, where A represents 10 and F represents 15. The reason 16 is suited to computer technology is that one hexadecimal digit precisely represents four bits (binary digits), and two digits represent one byte.

Uses and Measurements

16 appears in various contexts and measurements: 16 ounces equals one pound in the imperial weight system. In competitive sports, the round of 16 is a standard stage in football (soccer) tournaments. In education and legal systems of many countries, the age of 16 years marks a threshold for certain rights, though this varies from country to country.