44

Forty-four is the natural number that follows 43 and precedes 45. It is an even composite integer with prime factorization 2^2 × 11. Its positive divisors are 1, 2, 4, 11, 22, and 44. The sum of its proper divisors is 40, making 44 a deficient number.

In numeral systems, forty-four is written as XLIV in Roman numerals. In binary it is 101100, in octal 54, and in hexadecimal 2C.

In science, atomic number 44 corresponds to ruthenium (Ru), a transition metal in the platinum group used in various industrial applications, including electronics and catalysts.

Geography and history sections note several uses of the number. The 44th parallel north is a circle of latitude that crosses parts of North America, Europe, and Asia. The 44th state admitted to the United States was Oklahoma in 1907. Julius Caesar is traditionally dated to have been assassinated in 44 BCE, a pivotal event in Roman history.

In modern culture, Barack Obama is the best-known bearer of the label “the 44th President of the United States,” highlighting how the ordinal form of the number appears in political history. In computing and typography, the ASCII code 44 designates the comma character, a common punctuation mark.

Forty-four can also appear in various contexts, such as sports or measurements, often as a jersey number or a unit designation. As a repdigit, it features identical digits in decimal notation, two fours in succession.