perfect number #13 = 23562723457267347065789548996709904988477547858392600710143027597506337 283178622239730365539602600561360255566462503270175052892578043215543382 498428777152427010394496918664028644534128033831439790236838624033171435 922356643219703101720713163527487298747400647801939587165936401087419375 649057918549492160555646976