What's the minimum amount of people needed to repopulate Earth?

The minimum amount of people needed to repopulate Earth is difficult to determine and would depend on a variety of factors, but a population size of at least 500 individuals with sufficient genetic diversity would be necessary to ensure the long-term survival and success of the population.

This number is based on the concept of the "founder effect," which states that when a small group of individuals establishes a new population, they carry only a limited subset of the genetic diversity of the original population. As a result, the new population may be more vulnerable to genetic disorders and other problems, and a larger population size would be needed to ensure that the population is resilient and able to adapt to changing conditions.