1 (number)

1 (one; /ˈwʌn/ or UK /ˈwɒn/, also called unit, unity, and (multiplicative) identity), is a number, a numeral, and the name of the glyph representing that number. It represents a single entity, the unit of counting or measurement. For example, a line segment of unit length is a line segment of length 1.

As a number

One, sometimes referred to as unity, is the integer before two and after zero. One is the first non-zero number in the natural numbers as well as the first odd number in the natural numbers.

Any number multiplied by one is that number, as one is the identity for multiplication. As a result, one is its own factorial, its own square, its own cube, and so on. One is also the result of the empty product, as any number multiplied by one is itself. It is also the only natural number that is neither composite nor prime with respect to division, but instead considered a unit.

As a digit

The glyph used today in the Western world to represent the number 1, a vertical line, often with a serif at the top and sometimes a short horizontal line at the bottom, traces its roots back to the Indians, who wrote 1 as a horizontal line, much like the Chinese character 一. The Gupta wrote it as a curved line, and the Nagari sometimes added a small circle on the left (rotated a quarter turn to the right, this 9-look-alike became the present day numeral 1 in the Gujarati and Punjabi scripts). The Nepali also rotated it to the right but kept the circle small. This eventually became the top serif in the modern numeral, but the occasional short horizontal line at the bottom probably originates from similarity with the Roman numeral I. In some countries, the little serif at the top is sometimes extended into a long upstroke, sometimes as long as the vertical line, which can lead to confusion with the glyph for seven in other countries. Where the 1 is written with a long upstroke, the number 7 has a horizontal stroke through the vertical line.

Alicia Keys

Alicia Augello Cook (born January 25, 1981), known by the pseudonym Alicia Keys, is an American singer, songwriter, record producer, and actress. Keys released her debut album with J Records, having had previous record deals first with Columbia and then Arista Records. Keys' debut album, Songs in A Minor, was a commercial success, selling over 12 million copies worldwide. She became the best-selling new artist and best-selling R&B artist of 2001. The album earned Keys five Grammy Awards in 2002, including Best New Artist and Song of the Year for "Fallin'" becoming the second American recording artist to win five Grammys in one night. Her second studio album, The Diary of Alicia Keys, was released in 2003 and was also another success worldwide, selling eight million copies. The album garnered her an additional four Grammy Awards in 2005. Later that year, she released her first live album, Unplugged, which debuted at number one in the United States. She became the first female to have an MTV Unplugged album to debut at number one and the highest since Nirvana in 1994.