An online aliquot number definition
An aliquot part is any divisor of a number, not equal to the number itself. The divisors are often referred to as proper divisors. The aliquot parts of the number 24 are 1, 2, 3,4, 6, 8 and 12.
ALMOST PERFECT NUMBER
An almost perfect number is typically applied to the powers of 2 since the sum of the aliquot parts is 2n – 1, or just 1 short of being a perfect number. It follows that any power of 2 is a deficient number.
Alphametic numbers form cryptarithms where a set of numbers are assigned to letters that usually spell out some meaningful thought.
The numbers can form an addition, subtraction, multiplication or division problem. One of the first cryptarithms came into being in 1924 in the form of an addition problem the words being intended to represent a student’s letter from college to the parents.
The puzzle read SEND + MORE = MONEY. The answer was 9567 += 1085 = 10,652. Of course, you have to use logic to derive the numbers represented by each letter.