OFFSET
1,2
COMMENTS
Note that the smaller repunits R3=111, R4=1111, R5=11111 are semiprimes and have only 4 divisors, which is again the case for the next repunit R7=1111111. - M. F. Hasler, Oct 13 2011
LINKS
Eric Weisstein's World of Mathematics, Repunit
MATHEMATICA
Divisors[111111] (* Paolo Xausa, Sep 27 2023 *)
PROG
(PARI) divisors(111111) \\ Michel Marcus, Sep 08 2015
CROSSREFS
KEYWORD
nonn,fini,full,easy
AUTHOR
Philippe Deléham, Aug 28 2005
STATUS
approved