1 is the natural number following 0 and preceding 2, the Hindu-Arabic numeral for the number one (the unit). It is the smallest positive integer, and smallest natural number. 1 is the multiplicative identity, i.e. any number multiplied by 1 equals itself, for example: a ⋅ 1 = a \displaystyle a. 1 (one, unit, unity) is a number, numeral, and grapheme. It is the first and smallest positive integer of the infinite sequence of natural numbers. The number 1 is the first natural number after 0. Each natural number, including 1, is constructed by succession, that is, by adding 1 to the previous natural number. In scientific notation, it is written as 1 × 10 0. It has a total of 0 prime factors and 1 positive divisors. There is one positive integer (up to 1) that is relatively prime to 1. The prime factorization of 1 is 1. Since it has a total of 0 prime factors, 1 is a composite number. 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, as is still the case in Chinese script. 1 (number). Chinese hand sign 0:01 Pronunciation of the number 1. One (1) is the first natural number, followed by two, then followed by three. The Roman numeral for one is I. Babylonian number 1 A little block falls out of the sky, meets her numberling and discovers one wonderful world, singing and counting to one. Learn all about the number 1 with N. Learn the different ways number 1 can be represented. See the number one on a number line, five frame, ten frame, numeral, word, dice, dominoes, tally mark, fingers and picture representations. Tenth century “West Arabic” variation of the Nepali form of Hindu-Arabic numerals (compare Devanagari script १ (1, “éka”)), possibly influenced by Roman numeral Ⅰ, both ultimately from using a single stroke to represent the number one. The number 1 is the first natural number after 0. Each natural number, including 1, is constructed by succession, that is, by adding 1 to the previous natural number.