Not able to convert scientific notation to number in R

Question

Can anyone help me converting exp to numeric in R

> asd <-data.frame(a = c(1234254535343,423), b= c("a","f"))
> asd$a <- scientific(asd$a, digits = 3)
> asd
         a b
1 1.23e+12 a
2 4.23e+02 f

> asd$a <- format(asd$a, scientific = FALSE)
> asd
         a b
1 1.23e+12 a
2 4.23e+02 f

Expected output

> asd
         a      b
1 1234254535343 a
2 423           f