3 and 11
They don't. 21 has two prime factors. 42 has three prime factors.
1 , 33 , 3 , 11
All prime squares have three factors.
231 has exactly three prime factors. They are 3, 7, and 11.
That's an infinite list. Numbers with three factors are the squares of prime numbers.
By definition, a prime number has exactly two factors. So, there are no prime numbers with exactly three factors.
The only factors of 23, which is a prime number, are 1 and 23.
532
All composite numbers can be expressed as unique products of prime numbers. This is accomplished by dividing the original number and its factors by prime numbers until all the factors are prime. A factor tree can help you visualize this. Example: 210 210 Divide by two. 105,2 Divide by three. 35,3,2 Divide by five. 7,5,3,2 Stop. All the factors are prime.
To find the prime factors of 28 start with any factor pair of 28 and keep factoring the composite factors until all the factors are prime. 28 2 x 14 2 x 2 x 7 The three prime factors of 28 are 2, 2, 7.
All of them.
It is 625 when as a product of its prime factors is 5*5*5*5 = 625