A characterization of multiplicative (and additive) arithmetical functions is given. Using this characterization, we show that the group of multiplicative arithmetical functions is isomorphic to the group of additive arithmetical functions.
A Characterization of class groups via sets of lengths {II}
Characterization of digital $(0,m,3)$-nets and digital $(0,2)$-sequences in base $2$
A characterization of all equilateral triangles in \Bbb Z^3
![QR code for arXiv:1106.5320 [math.NT]](http://oss.arxitics.com/images/favicon.svg)