Anxiety Disorder Statistics. Anxiety Disorders affect 18.1 percent of adults in the United States (approximately 40 million adults between the ages of 18 to 54).
Perfect square. Perfect square is an element of algebraic structure which is equal to the square of another element. Square number, a perfect square integer.
Meaning of perfect numbers. A perfect number: a number is perfect when the sum of its divisors (except the number itself) equals the given number. Theorem connecting perfect and prime numbers. 6 : The divisors of 6 are 1,2,3 & 6.