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.
The integer n = 6 has the proper divisors 1,2,3. The sum of these divisors is 6, the number itself. A natural number n for which the sum of proper divisors is n is called a perfect number. So, 6. is a perfect number. All presently known perfect numbers are even. Here are the smallest 12 perfect numbers: 6,28,496,8128,33550336,8589869056,137438691328.