16
16
All prime squares have exactly three factors.49 has exactly three factors: 1, 7, and 49.
There are three of them with exactly five factors.
A prime number has exactly two factors.
81 has 5 factors: 9x9 3 x 27 1 x 81
Squares of prime numbers have exactly three factors.
16
All prime squares have exactly three factors.49 has exactly three factors: 1, 7, and 49.
16 does.
16
16
There are three of them with exactly five factors.
attitude, thinking and surroundings
Six has four factors and is in between the twin primes 5 and 7.
88 has exactly eight factors (1, 2, 4, 8, 11, 22, 44 & 88)
In that range, only 100 has exactly 9 factors.
A number that has exactly an odd number of factors is a power of another number. A number between 10 and 30 that is a power is 16. It is 24 (as well as 42) and its factors are 1, 2, 4, 8, and 16.
No numbers between 1 and 100 have exactly eleven factors. 60, 72, 84, 90 and 96 each have twelve factors.