Prime squares have three factors. 4, 9, 25
4, 9, 25 and 49 They are squares of prime numbers.
Prime numbers have two factors. 2, 3 and 5 are prime numbers.
Prime numbers like 2, 3, 5 and 7
Prime factors of 18 are 2 and 3 Prime factors of 45 are 3 and 5
Squares of prime numbers have exactly three factors.
Numbers with exactly three factors are squares of prime numbers.
All numbers that are the square of primes have exactly 3 factors.
By definition, a prime number has exactly two factors. So, there are no prime numbers with exactly three factors.
Prime squares
The squares of all prime numbers above 2 have exactly 3 factors.
A number has exactly three factors if and only if it is the square of a prime number.
Prime numbers have exactly two factors. 3 has exactly two factors: 1 and 3. So 3 is prime. Composite numbers have more than two factors. 4 is composite because it has three factors: 1, 2, and 4.
There are an infinite number of them. 8 has three prime factors, 30 is the first with three distinct prime factors.
3 is a prime number because it has exactly two factors which are whole numbers: itself and one. This is the definition of a prime.
Squares of prime numbers, like 4, 9 and 25.
Prime squares have three factors. 4, 9, 25