+123 1. Use the digits 2, 4, 5, and 7 each once to create two prime numbers. What is the smallest possible product of two prime numbers created from these digits?
2. Most non-negative integers can be written as the sum of a prime number plus a perfect square. For instance, 21 can be written as What is the smallest number greater than 1 which cannot be expressed in this way?
3. How many sets of 3 primes sum to 20?
4. Find the smallest positive integer with the same number of positive divisors as 9775.
THX FOR ALL YOUR HELP!!
