Prime numbers
there are 3 no.2,3 & 5
14 (I think).
Numbers with exactly 6 factors are perfect squares of prime numbers. The prime factorization of a number with exactly 6 factors is in the form ( p^2 ), where ( p ) is a prime number. There are 10 prime numbers less than 30: 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29. So, there are 10 numbers less than 30 that have exactly 6 factors.
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.
Numbers with exactly 6 factors are perfect squares of prime numbers. The prime factorization of a number with exactly 6 factors is in the form ( p^2 ), where ( p ) is a prime number. There are 10 prime numbers less than 30: 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29. So, there are 10 numbers less than 30 that have exactly 6 factors.
11
Prime numbers
They are: 2 3 5 and 7 all of which are prime numbers
Just 36.
there are 3 no.2,3 & 5
14 (I think).
Perfect squares have an odd number of factors. There are 31 perfect squares less than 1000.
They all are prime numbers except 1
All but the square numbers - 53 of them.
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.
99, but that's probably not what you want to know. There are 21 factors of 360 that are less than 100.