unusual property of some numbers with 8 divisors (i.e. 2014)
Source: Rioplatense Olympiad 2014 level 3 P2
September 5, 2018
number theorynumber of divisorsDivisors
Problem Statement
El Chapulín observed that the number has an unusual property. By placing its eight positive divisors in increasing order, the fifth divisor is equal to three times the third minus . A number of eight divisors with this unusual property is called the red number . How many red numbers smaller than exist?