2. That is the only one.
And the 11 divisors are 2k where k = 0, 1, ,2, ... , 10
The squares -- nine of them.
The set of positive odd integers.
1, 4, 9, 16, 25, 36, 49, 64, 81, 100 -- the square numbers.
The positive integers less than 11 are the natural numbers 1-10.That is to say 1,2,3,4,5,6,7,8,9 and 10.
One less than 10000.
The squares -- nine of them.
35 is a deficient number because the sum of its proper divisors is less than the number itself.
There are 1,963 such integers. Every factor of a number has a pair. The only time there will be an odd number of factors is if one factor is repeated, ie the number is a perfect square. So the question is really asking: how many positive integers less than 2008 (in the range 1 to 2007) are not perfect squares. √2007 = 44 and a bit (it lies between 44 and 45) So there are 44 integers less than (or equal to) 2007 which are perfect squares → 2007 - 44 = 1963 integers are not perfect squares in the range 1-2007 and have an even number of factors (divisors).
The set of positive odd integers.
1, 4, 9, 16, 25, 36, 49, 64, 81, 100 -- the square numbers.
The sum of the first positive odd integers less than 101 is 10,000.
the negative integers are below 0, for example -6.
There are 44 positive integers less than 2,010 that have an odd number of factors.
Positive integers are greater than zero. Negative integers are less than zero.
666 integers.
49
The sum of all the digits of all the positive integers that are less than 100 is 4,950.