The ground-state hyperfine splitting values of high-[Formula Presented] hydrogenlike ions are calculated. The relativistic, nuclear, and QED corrections are taken into account. The nuclear magnetization distribution correction (the Bohr-Weisskopf effect) is evaluated within the single-particle model with the [Formula Presented] factor chosen to yield the observed nuclear moment. An additional contribution caused by the nuclear-spin-orbit interaction is included in the calculation of the Bohr-Weisskopf effect. It is found that the theoretical value of the wavelength of the transition between the hyperfine-splitting components in [Formula Presented] is in good agreement with experiment.