The decimal 3,902 Number in the Braille Alphabet is
Número = Number sign. Means that it opens a number instead of a sequence of letters.
Milhar = Thousands sign. It is an option to use it.
All natural divisors of 3,902 are:
1, 2, 1951, 3902
And that is the number factored 3,902 = 2 x 1951 (it is not prime)