9000 integers.
The squares -- nine of them.
There are 80 such integers.
10
n(n+1) <10000 so n is close to square-root of 10000 which is 100. Obviously 100x101 is too much, but 99x100 is OK
125
49
666 integers.
There are 44 positive integers less than 2,010 that have an odd number of factors.
There are 130 positive integers less than 1,000 that are divisible by seven but not divisible by 11
There are 544 positive integers less than 1,000 that are either divisible by two or by 11.
Eight.
6
9000 integers.
The squares -- nine of them.
7 of them.
There are 80 such integers.