There are 12 numbers less than 150 which have an odd number of factors: 1,4,9,16,25,36,49,64,81,100,121,144.
The prime numbers less than 13 have the fewest factors. They are:235711
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.
There are 31 numbers less than 1,000 which have an odd number of factors. They are: 1,4,9,16,25,36,49,64,81,100,121,144,169,196,225,256,289,324,361,400,441,484,529,576,625,676,729,784,841,900,961.
1 is the number less than fifty with the fewest number of factors. All other numbers have at least two factors (1, and the integer itself).
Prime numbers have two factors. Composite numbers have more than two. Numbers with less than two are neither.
The three greatest whole numbers less than 200 that each have an odd number of factors are 144, 169 and 196.
No odd number less than hundred has 12 factors other numbers which has 12 factors are 60, 72, 84, 90 and 96. But they all are even numbers. The answer will be different if you consider negative numbers, however.
The numbers for which the sum of its proper factors is 1 less than the number is the powers of 2; less than 50 these are: 2, 4, 8, 16 & 32.
There are four odd numbers less that 100 that have 6 factor. This does not compare with even numbers that have 12 factors!
Perfect squares have an odd number of factors. There are 31 perfect squares less than 1000.
Products will be greater unless your number set includes a number less than 1.