IsPrime.cs

IsPrime.cs

using System;
using System.Collections.Generic;
using System.Linq;

var number = 45673;

var multiples = Multiples(number);

Console.WriteLine($"{number} is " + 
	$"{(multiples.Any() ? "not " : "")}prime");

foreach (var multiple in multiples)
{
	Console.WriteLine(multiple);
}

IEnumerable<string> Multiples(int number)
{
	return from n1 in Enumerable.Range(2, number/ 2) 
		   from n2 in Enumerable.Range(2, n1) 
		   where n1 * n2 == number 
		   select $"{n1} x {n2} => {number}"; 
}