The half-life of carbon-14, which is approximately 5,730 years, remains constant regardless of the number of carbon-14 atoms present. This means that if you increase the number of carbon-14 particles in a sample, the half-life does not change; it is still 5,730 years for all quantities of carbon-14.
This teaches us that half-life is a constant number. The half-life of a radioactive isotope is an intrinsic property of that isotope and is independent of the amount of material present.