1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers.
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.
Roman numerals are a system of numerical notation based on the ancient Roman system. The symbols are I, V, X, L, C, D, and M, standing respectively for 1, 5, 10, 50, 100, 500, and 1,000 in the Hindu-Arabic numeral system.
Your guide to the number 1, an odd number which is uniquely neither prime nor composite. Mathematical info, prime factorization, fun facts and numerical data for STEM, education and fun.