The default SSH login port 22 can be easily changed. The main idea behind changing the port is security though it is not a big deal but still it can protect against some automated attacks that target port 22.
Open the sshd_config file in vi or any other editor of your choice
sudo vi /etc/ssh/sshd_config
Restart sshd service
systemctl restart sshd.service
CentOs usually has selinux enabled by default. To check the status of selinux use this command
semanage port -a -t ssh_port_t -p tcp 50001
Where 50001 is the custom port number replace it with the port number you assigned in the previous step in the sshd_config file.
Finally systemctl restart sshd.service