Numbers such that Divisor Count divides Phi divides Divisor Sum/Examples/15

Examples of Numbers such that Tau divides Phi divides Sigma
The number $15$ has the property that:
 * $\map \tau {15} \divides \map \phi {15} \divides \map \sigma {15}$

where:
 * $\divides$ denotes divisibility
 * $\tau$ denotes the divisor counting (tau) function
 * $\phi$ denotes the Euler $\phi$ (phi) function
 * $\sigma$ denotes the $\sigma$ (sigma) function.