30 does.
2 x 3 x 5 = 30
The square of any prime number has exactly three factors: 22, 32, 52, etc.
30 = 2 x 3 x 5 = 30
Prime numbers
30 does.
They all are prime numbers except 1
27
By definition, a prime number has exactly two factors. So, there are no prime numbers with exactly three factors.
How about 105 whose prime factors are 3, 5 and 7
30 (2 x 3 x 5) and 42 (2 x 3 x 7) are the only numbers less than 60 having three different prime factors.
30, 42, 66, 70 and 78.
105=3*5*7it has to be only three factors and they are all prime105
4, 9, 25, and 49
42 and its next three multiples.
105 is one such number.
The sum of the three greatest prime numbers that are less than 39 is 97.