
The Millionth Number with at Least One Million Prime Factors
Consider the natural numbers having at least $5$ prime factors, which don't have to be distinct.
Sorting these numbers by size gives a list which starts with:
- $32=2 \cdot 2 \cdot 2 \cdot 2 \cdot 2$
- $48=2 \cdot 2 \cdot 2 \cdot 2 \cdot 3$
- $64=2 \cdot 2 \cdot 2 \cdot 2 \cdot 2 \cdot 2$
- $72=2 \cdot 2 \cdot 2 \cdot 3 \cdot 3$
- $80=2 \cdot 2 \cdot 2 \cdot 2 \cdot 5$
- $96=2 \cdot 2 \cdot 2 \cdot 2 \cdot 2 \cdot 3$
- $\cdots$
So, for example, the fifth number with at least $5$ prime factors is $80$.
Find the millionth number with at least one million prime factors.
Give your answer modulo $123454321$.