The latest line should be

    n = 19227; k = 6018; Nx = 10^6;
    N[CDF[HypergeometricDistribution[n, k, Nx], 200], 100] - 
     N[CDF[HypergeometricDistribution[n, k, Nx], 1], 100]

> `0.99999999999980234474426879880990803313584713194819457153196994629316
38734132748161581793705151966009`

See [Wiki](https://en.wikipedia.org/wiki/Cumulative_distribution_function) for info.