### Related

##### divsum-do-print

d(n):=divsum(n)-n;

isa(n):=if d(d(n))=n ...

c:0;

Calculate

divsum(12);

divsum(24);

divsum(12)-12;

Calculate

? divsum;

Calculate

##### divsum-numer

divsum(5^5*13^7*43^4*...

Calculate

##### divsum-numer

divsum(5^2*7*13*41*43...

Calculate

a : 16800;

b : -990;

divsum(b);

Calculate

##### divsum-do

for k from 1 thru 50...

Calculate

##### divsum-numer

divsum(37^3*41^3)/(2*...

Calculate

##### divsum-numer

divsum(5^3*7^3*13^3*1...

Calculate

##### divsum-numer

divsum(5^2*7*13*19*23...

Calculate

### divsum

Run Example
```(%i1)d(n):=divsum(n)-n;
(%o1)                        d(n) := divsum(n) - n
(%i2) abu(n):=if d(n) >
n then true else false;
(%o2)                   abu(n) := if d(n) > n then true
(%i3) l : list();
(%o3)                               list()
(%i4)  for i : 0 thru 100 do (if abu(i) then (print(i,d(i)),l:append(l,list(i))));
0 1
12 16
18 21
20 22
24 36
30 42
36 55
40 50
42 54
48 76
54 66
56 64
60 108
66 78
70 74
72 123
78 90
80 106
84 140
88 92
90 144
96 156
100 117
(%o4)                                done
(%i5) l;
(%o5) list(0, 12, 18, 20, 24, 30, 36, 40, 42, 48, 54, 56, 60, 66, 70, 72, 78,
80, 84, 88, 90, 96, 100)
(%i6) ```
Run Example
```divsum(5^3*7^3*13^2*19^2*23^2*29^2*31*37*41*43)/(2*5^3*7^3*13^2*19^2*23^2*29^2*31*37*41*43), numer;
(%o1)                          1.000562103706704
(%i2) ```
Run Example
```divsum(5^2*7^5*13^5*19^5*23^5*29^2*31*37*41*43)/(2*5^2*7^5*13^5*19^5*23^5*29^2*31*37*41*43), numer;
(%o1)                          0.99523356308197
(%i2) ```

Help for Divsum