25th

The 25th, or twenty-fifth, is the ordinal form of the number 25. It denotes position in a sequence and is used in dates and lists, for example the 25th of December or the 25th item in a document. As a calendar term, the 25th occurs in every month and is commonly associated with holidays or events on the calendar, such as Christmas on December 25.

In mathematics, 25 is a perfect square (5 squared) and a composite number with divisors 1, 5, and 25. It is written XXV in Roman numerals and is 11001 in binary.

In law and government, the Twenty-Fifth Amendment to the United States Constitution, ratified in 1967, provides for presidential succession and incapacity. The term is also used for military units, such as the 25th Infantry Division, and for anniversaries, where the 25th anniversary is traditionally called the silver anniversary.

In statistics and data analysis, the 25th percentile marks the value below which one quarter of observations fall. The 25th is thus a common reference point in describing distributions and standards in various fields.