natural integer number for which the sum of its proper strict divisors (other than itself) is less than the number itself
Demonstration, with Cuisenaire rods, of the deficiency of the number 8
In number theory, a deficient number or defective number is a positive integer n for which the sum of divisors of n is less than 2n. Equivalently, it is a number for which the sum of proper divisors (or aliquot sum) is less than n. For example, the proper divisors of 8 are 1, 2, and 4, and their sum is less than 8, so 8 is deficient.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).