There is no specific name: you just call it a number with 2 or more digits or a multi-digit number.
a Quadrillion is a 16 digit number
No. When adding the smallest 2 digit number (= 10) to the smallest 2 digit number (again, 10) the result is a 2 digit number (10 + 10 = 20). When adding the largest 2 digit number (= 99) to the largest 2 digit number (again, 99) the result is a 3 digit number (99 + 99 = 198). As you can see, you'll either get a 2 or 3 digit number, but never a 4 digit number.
2
2 digit number
I suggest you just call it that - a "35-digit number".
I would just call it a "400-digit number".
0
10 is the smallest 2 digit number.
You would call it million.
Because -99 is a two digit number and it is smaller.10 is the smallest positive 2-digit number.Because -99 is a two digit number and it is smaller.10 is the smallest positive 2-digit number.Because -99 is a two digit number and it is smaller.10 is the smallest positive 2-digit number.Because -99 is a two digit number and it is smaller.10 is the smallest positive 2-digit number.
This first digit is the first number. In this case the first digit is the number 2.