Numbers that are prime can't be multiples of 10.
Multiples of 10 can't be odd.
There are 10 numbers less than 101 which have an odd number of factors: 1,4,9,16,25,36,49,64,81,100.
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.
11,22,33,44,55,66,77,88,99
4, 9, 25 and 49 They are squares of prime numbers.
A whole number has an odd number of unique factors if and only if it is a perfect square. The perfect squares less than 10 are 0, 1, 4, and 9. Therefore, there are four whole numbers less than 10 that have an odd number of unique factors.
All even numbers greater than 2 have even proper factors, since they all have 2 as a proper factor.
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.
Square numbers, like 36 and 64.
There are four odd numbers less that 100 that have 6 factor. This does not compare with even numbers that have 12 factors!
60, 72, 84, 90 and 96 each have twelve factors.
0, 1, 2, 3
The most factors any odd number less than 100 has is 6. There are 4 numbers which have 6 factors:45, 63, 75 & 99.
There are 10 numbers less than 101 which have an odd number of factors: 1,4,9,16,25,36,49,64,81,100.
44 and 45 75 and 76 98 and 99
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97
No.
Prime numbers