15 is composite number 17, 19 and 23 are prime numbers.
23
It is 23
It is not a prime number. 19 x 23= 437.
21 is composite.
It is 23
27
27
15 is composite number 17, 19 and 23 are prime numbers.
19 and 23 are prime.
It is 23 followed by 29
19 + (44 + 23) = (19 + 44) + 23
Since the two number are coprime, the answer is 23*19 = 437
19 is a prime number. Its only factors are 1 and 19. 21 is a composite number. Its factors are 1, 3, 7, and 21. 23 is a prime number. Its only factors are 1 and 23.
Choose any prime number before 23 because the given numbers are all prime numbers
23
19+17+23+17=76 76/4 (the number of numbers) = 19