Problem #PRU-100507

Problems Number Theory Arithmetic operations. Number identities

Problem

George knows a representation of number “8” as the sum of its divisors in which only divisor “1” appears twice: \[8=4+2+1+1.\] His brother showed George that such representation exists for number “16” as well: \[16=8+4+2+1+1.\] He apologies for forgetting an example considering number “32” but he is sure once he saw such representation for this number.

(a) Help George to work out a suitable representation for number “32”;

(b) Can you think of a number which has such representation consisting of 7 terms?

(c) Of 11 terms?

(d) Can you find a number which can be represented as a sum of its divisors which are all different (pay attention that we don’t allow repeating digit “1” twice!)?

(e) What if we require this representation to consist of 11 terms?