49

49 is a natural number that follows 48 and precedes 50. It is an odd composite number, with a prime factorization of 7 squared (7^2). Its positive divisors are 1, 7, and 49, making it the seventh square number.

In number theory, 49 is notable as the square of a prime. It is also interesting in base representations: in base 7, 49 equals 100_7; in binary, it is 110001; in hexadecimal, it is 31. As a decimal value, it is often used in everyday counting and measurements where a square helps indicate symmetry or completeness.

In science, 49 is the atomic number of indium, a post-transition metal used in electronics, alloys, and solders. Indium was discovered in 1863 and named for the indigo spectral lines it produced.

In culture and geography, the number 49 appears in several contexts. The San Francisco 49ers, an NFL team, are named after the 1849 California Gold Rush. The 49th parallel north forms a significant portion of the border between the United States and Canada. The counting of the Omer, a Jewish practice spanning 49 days between Passover and Shavuot, is another notable association.

In computing and typography, the decimal value 49 corresponds to the ASCII code for the character '1'. This linkage between the numeral and its encoded representation is sometimes noted in discussions of character encoding.