Number 681 is an integer that follows 680 and precedes 682. It is an odd number and can be expressed as the sum of two prime numbers, specifically 337 and 344. In mathematics, it is often analyzed in various contexts, such as number theory and sequences. In terms of its properties, 681 can be factored into 3 and 227, indicating that it is a composite number. Additionally, it can be represented in different numeral systems, such as binary (1010101001) and hexadecimal (2A9). These representations are useful in computer science and digital applications.