A double digit number, triple digit number........
That refers to a number that has more than one digit.
That means that the number has more than one digit.
It is 3823.
multi-digit
We call them by the number of their digits. Two-digit number, three-digit number and so on.
6849 and 0213
That refers to a number that has more than one digit. For example, 416 is a number; the individual symbols, 4, 1, and 6, are its digits. Since the number 416 has more than one digit, it is multidigit.
2.3
43
26
There is no specific name: you just call it a number with 2 or more digits or a multi-digit number.
50