Look here:
53 59 61 67 71 73
When all of them are prime numbers,then just multiply the numbers to get the LCM of those 3 numbers.
Nobody. That is because there is no pattern to prime numbers. There are various methods to find some classes of prime numbers but none that will find all of them.
The prime numbers from 75 through 100 are: 79, 83, 89, 97
The way to know the Prime Numbers is to find out if they can only Multiplied Once ,The way to know Composite Numbers is to find out if they can be Multiplied Twice
Scroll down to related links and look at "List of prime numbers - Wikipedia".
The sum of all prime between numbers 1 and 400 (2 through 399) is 13,887.
I've found all the prime numbers...
53,59,61,67,69,71,73.
All prime numbers are special numbers because they help us to find the lowest common multiple of numbers and their highest common factor.
The only even prime number is 2.
All the prime numbers between 50 and 75 are: 53, 59, 61, 67, 71 and 73.
Since there is an infinite set of prime numbers the answer would be infinity.