Find a six digit number containing no zeros and no repeated digits that satisfies the following conditions: the sum of the last four digits is twice then sum of the first two digits; the fourth digit is even; the last digit is the product of the second and fifth digits; and the sum of all six digits is 21.

Got it. Not too difficult a puzzle - start with the fact that the sum of all six digits = 21 with no 0's, and that tells you what the 6 digits are. The fact that the last digit = the 2nd digit times the 5th digit nails down what that last digit must be, and leaves two choices for the 2nd and 5th. From there it's up to you. Post back with your attempt at continuing the solution.