The number 681 is an integer that follows 680 and precedes 682. It is an odd number and can be expressed as the product of its prime factors, which are 11 and 61. In mathematics, it can also be classified as a composite number since it has divisors other than 1 and itself. In terms of its representation in different numeral systems, 681 is written as 1010101001 in binary and as 2A9 in hexadecimal. The number can also be found in various contexts, such as in mathematics, statistics, and even in everyday counting scenarios.