galois.prev_prime

galois.prev_prime(x)

Returns the nearest prime \(p \le x\).

Parameters

x (int) – A positive integer.

Returns

The nearest prime \(p \le x\).

Return type

int

Examples

In [1]: galois.prev_prime(13)
Out[1]: 13

In [2]: galois.prev_prime(15)
Out[2]: 13