There are 10 numbers less than 101 which have an odd number of factors: 1,4,9,16,25,36,49,64,81,100.
The prime numbers less than 13 have the fewest factors. They are:235711
They all are prime numbers except 1
The ones with less than three factors.
All prime numbers less than 50 have exactly two factors. e.g. 2,3,5,7,11,13,17,19,23,29,31,37,41,43 & 47.
There are a few numbers that are less than 19 and have more than 4 factors. The number 10 is less than 19 and has more than four factors.
If the two numbers have no prime factors in common, their LCM will be their product. If there are prime factors in common, their LCM will be less than their product.
If the two numbers have no common factors other than 1, the LCM will be their product. If there are other common factors, the LCM will be less.
Four numbers less than thirty, 12, 18, 20, and 28, each have exactly 6 factors.