In general, numbers in R are treated as numeric objects.
3 # numeric object  3 3L # explicitly gives an integer  3 Inf # a special number which represents infinity  Inf 1/0  Inf 1/Inf # can be used in calculations  0 0/0 # NaN ("not a number"); also, seen as a missing number  NaN
Numerics are also decimal values in R. This happens by default, so that if you create a decimal value for x that is will be of the numeric type.
x = 8.3 # create x which a decimal value x # print the value of x  8.3 class(x) # what is the class of x?  "numeric"
Even when assigning an integer to a variable such as N, it is still being retained as a numeric value.
N = 43 N #print the value of N  43 class(N) # what is the class of N?  "numeric"
You can further confirm that N is not an integer by using the is.integer function.
is.integer(N) # is N an integer?  FALSE is.numeric(N) # is N numeric?  TRUE