Alright, I shall answer.
Any number which takes a negative sign (e.g. -20, -41 etc.) is a negative number. Since the sign itself shows it is a negative number, there is no confusion.
Coming to imaginary number, the square root of -1 is said to be imaginary, because our knowledge does not go beyond a certain limit to find out what it could be. Here too, as the imaginary number is an abstract concept, it is not understood by all.
So, when we are sure that a number is positive and not just greater than Zero, but equals 'One', it shows it is 'Whole', 'Total', 'Perfect' etc.
Kannadasan wrote thus for a film named 'Valarpirai':
"Poojiyathukulle oru Rajjiyathai aandu kondu
Puriyaamale Iruppan oruvan; Avanai
Purindhu kondaal avan thaan Iraivan".