EN
Let λ denote Carmichael's function, so λ(n) is the universal exponent for the multiplicative group modulo n. It is closely related to Euler's φ-function, but we show here that the image of λ is much denser than the image of φ. In particular the number of λ-values to x exceeds $x/(log x)^{.36}$ for all large x, while for φ it is equal to $x/(log x)^{1+o(1)}$, an old result of Erdős. We also improve on an earlier result of the first author and Friedlander giving an upper bound for the distribution of λ-values.