  Let $g(f)$ denote the maximum of the differences (gaps) between two
consecutive exponents occurring in a polynomial $f$. Let $\Phi_n$ denote the
$n$-th cyclotomic polynomial and let $\Psi_n$ denote the $n$-th inverse
cyclotomic polynomial. In this note, we study $g(\Phi_n)$ and $g(\Psi_n)$ where
$n$ is a product of odd primes, say $p_1 < p_2 < p_3$, etc. It is trivial to
determine $g(\Phi_{p_1})$, $g(\Psi_{p_1})$ and $g(\Psi_{p_1p_2})$. Hence the
simplest non-trivial cases are $g(\Phi_{p_1p_2})$ and $g(\Psi_{p_1p_2p_3})$. We
provide an exact expression for $g(\Phi_{p_1p_2}).$ We also provide an exact
expression for
  $g(\Psi_{p_1p_2p_3})$ under a mild condition. The condition is almost always
satisfied (only finite exceptions for each $p_1$). We also provide a lower
bound and an upper bound for $g(\Psi_{p_1p_2p_3})$.
