I have a favorite number, which so happens to be a positive integer, and it satisfies the following properties:
It can be expressed as the product of 5 prime numbers .
It has 5 proper divisors.
The sum of digits is also 5.
What is my favorite number?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Let the positive integer is n .It can be expressed as product of 5 primes.So n = p 1 p 2 p 3 p 4 p 5 .
No of proper divisor is 5 .So ,total divisors 5 + 1 = 6 .Each power of primes is 1 Then total number if facotrs will be 2 5 = 3 2 .
6 = 2 × 3 = 1 × 6 .pwers of 2 − 1 and 3 − 1 will not be allowed because then it cannot be expressed of 5 primes.So power ( 6 − 1 ) will be accepted which also be expressed as product of 5 primes.Now n = p 5 .The smallest n will be n = 2 5 = 3 2 which also satisfies third condition.