The divisors of a number are the positive whole numbers that divide into it evenly. For example the divisors of 6 are: 1, 2, 3, and 6.
Notice that 6 has four divisors. If you count how many divisors the number has your answer might be even (6 has 4 divisors) or it might be odd (1 has only 1 divisor, namely itself). How many of the numbers from 1 to 400 have an odd number of divisors?
