A pluperfect number is a type of number in number theory that is defined as a positive integer that is equal to the sum of its proper divisors, excluding itself. This means that if you take all the divisors of the number, add them together, and leave out the number itself, the total will equal the original number. An example of a pluperfect number is 6, which has divisors 1, 2, 3 that sum to 6. Pluperfect numbers are closely related to the concept of perfect numbers, which are numbers that equal the sum of their proper divisors, including 1. The study of pluperfect numbers is part of a broader field in mathematics known as number theory, which explores the properties and relationships of integers. While pluperfect numbers are less commonly discussed than perfect numbers, they still hold interest for mathematicians studying the characteristics of numbers.