1, 2
1, 5
The only number that ONLY has two and five as factors is 10, which has two digits, so there are no numbers that are three digits long and ONLY have two and five for factors. However, if you are asking what the largest three digit number that has two and five for factors, it would be the largest three digit number with ten as a factor, as ten the the LCM of two and five, and that would be 390.
30
10 and 20, among others.
1,000 has two prime factors; two and five: 2 x 5 = 10
30 and 60
700 Divide by two. 350,2 Divide by two. 175,2,2 Divide by five. 35,5,2,2 Divide by five. 7,5,5,2,2 Stop.
Five and 23 are the two prime factors of 115.
3
7 is a prime number. The only factors of a prime number are 1 and itself, so 7 only has two factors.
There are no prime numbers with three factors. By definition, a prime number has exactly two factors - 1 and itself.
60, 120, 180.....
2081 has two factors, one of them is prime. 72570 has thirty-two factors, five of them are prime. 50 has six factors, three of them are prime.