The largest integer that is not the product of two or more different primes would be the largest prime number. Because there are an infinite number of prime numbers, there is no largest integer that is not the product of two or more different primes.
The two smallest prime numbers are 2 and 3. So, the smallest number that is a product of two different primes that are squared is 22 x 32 = 36.
Since there are infinitely many primes, there are infinitely many numbers that are products of 3 primes.
95 is the product of two primes, 5 and 19.
59 is a prime number.
no the smallest number that is divisible by four different primes would be 210
Yes, always. This is the easiest way to find the LCM of two (or indeed any number of) primes.
Writing a number as the product of its prime factors is called prime factorization.