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.

1，是一个阿拉伯数字。 1是一个自然数，是最小的正整数，是最小的正奇数。 1是一个有理数，是一位数，也是奇数。 1既不是质数也不是合数。 1的n次方（n∈R）都等于1。 1的倒数是它本身。 一个或者 …

【看中国2026年1月7日讯】（看中国记者李净瑶综合报导）2026年1月4日，中共军方展开“全军开训”。此次，官方对开训的报导只字不提 习近平 和习的强军口号。分析认为，全军开训不提习近平让人怀 …

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. …

1 is 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, …

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 …

Dec 22, 2025 · Although the number 1 used to be considered a prime number, it requires special treatment in so many definitions and applications involving primes greater than or equal to 2 that it is …

1 （一 、 壹）是最小的 正整数，也是继 0 第二小的 自然数。 阿拉伯数字“1”的形状由 古苏美尔 和 巴比伦 符号演变而来。 在数学中，1为乘法单位元，即任何数字与1相乘皆等于其本身。 按照惯例，1不 …

prime, any positive integer greater than 1 that is divisible only by itself and 1—e.g., 2, 3, 5, 7, 11, 13, 17, 19, 23, ….

Explore the curious properties of number 1, an odd number which is uniquely neither prime nor composite. Includes mathematical info, prime factorization, divisors, bases and much more!