Is the apartment that I built with my own money on my deceased father's land my property or that of all the heirs, and how is the inheritance divided among the heirs (wife, two sons, two daughters)?

If the heirs are limited to those mentioned, the wife receives one-eighth due to the presence of a lineal descendant, as Allah Almighty says: "But if you have a child, then for them is one eighth of what you leave." The remainder goes to the two sons and two daughters by way of ta'sib (residuary heirship), with the male receiving the share of two females, as Allah Almighty says: "Allah instructs you concerning your children: for the male, what is equal to the share of two females." Thus, the inheritance is divided into 48 shares: the wife receives 6 shares, each son receives 14 shares, and each daughter receives 7 shares. It is recommended to consult the Sharia courts regarding inheritance matters due to their seriousness and to ensure there are no other heirs, bequests, or debts.