2.

Mathematical Skills: part 1

I Know you are a man of science and logic so let's start with few simple mathematical riddles

There is (at least) one number formed by 7 digits (which can be only 1,2,3,4,5,6,7). Each of those digits is present only once and the sum of 2 consecutive digits is equal to or the sum of the first 2 digits or to the sum of the last 2 digits.

What number is it? More than one solution is possible.