Number 684 is an integer that follows 683 and precedes 685. It is an even number, meaning it is divisible by 2 without a remainder. In terms of its prime factorization, 684 can be expressed as 2 × 342, and further broken down to 2 × 2 × 171, which shows that it has multiple factors. In mathematics, 684 can be represented in various numeral systems. For example, in Roman numerals, it is written as DCLXXXIV. Additionally, in binary, it is represented as 1010101100. This versatility in representation highlights the number's significance in different mathematical contexts.