1. ## Odd divisor question

98000 = 2^4 * 5^3 * 7^2

Compute the number of odd divisors of 98000

Im not what i need to do to start this

2. ## Re: Odd divisor question

You already have the prime decomposition, so any combination not including a factor of 2 will be odd...

3. ## Re: Odd divisor question

Originally Posted by inayat
98000 = 2^4 * 5^3 * 7^2
Compute the number of odd divisors of 98000
Im not what i need to do to start this
If $P=2^g\cdot3^h\cdot5^j\cdot7^k\cdot11^m\cdot13^n$ then $P$ has $(g+1)(h+1)(j+1)(k+1)(m+1)(n+1)$ factors. Of those $(h+1)(j+1)(k+1)(m+1)(n+1)$ and $h(g+1)(h+1)(j+1)(k+1)(m+1)(n+1)$ even.