Expert: Abe Mantell - 1/8/2007

Question
How do I describe in vocabulary form what a deficient number is and what an abundant number is?

Answer
deficient number - A positive integer the sum of whose divisors, including 1 but excluding itself, is less than itself. Also known as defective number.
Examples: 8, since 1+2+4<8; 10, since 1+2+5<10

abundant number - A positive integer the sum of whose divisors, including 1 but excluding itself, is greater than itself. Also known as redundant number.
Examples: 12, since 1+2+3+4+6>12; 18, since 1+2+3+6+9>18