The prime numbers less than 100 that contain an 8 are 83 and 89. So, there are two prime numbers that are less than 100 and contain an 8.
Prime numbers
There are a few numbers that are less than 19 and have more than 4 factors. The number 10 is less than 19 and has more than four factors.
Four numbers less than thirty, 12, 18, 20, and 28, each have exactly 6 factors.
The numbers for which the sum of its proper factors is 1 less than the number is the powers of 2; less than 50 these are: 2, 4, 8, 16 & 32.
The prime numbers less than 100 that contain an 8 are 83 and 89. So, there are two prime numbers that are less than 100 and contain an 8.
Prime numbers
They all are prime numbers except 1
There are a few numbers that are less than 19 and have more than 4 factors. The number 10 is less than 19 and has more than four factors.
If the two numbers have no common factors other than 1, the LCM will be their product. If there are other common factors, the LCM will be less.
The ones with less than three factors.
Four numbers less than thirty, 12, 18, 20, and 28, each have exactly 6 factors.
There are 12 numbers less than 150 which have an odd number of factors: 1,4,9,16,25,36,49,64,81,100,121,144.
The numbers for which the sum of its proper factors is 1 less than the number is the powers of 2; less than 50 these are: 2, 4, 8, 16 & 32.
If the GCF of a given pair of numbers is 1, the LCM will be equal to their product. If the GCF is greater than 1, the LCM will be less than their product. Or, stated another way, if the two numbers have no common prime factors, their LCM will be their product.
11,22,33,44,55,66,77,88,99
10,20,30,40,50,60,70,80,90