You have asked 2 different questions here with 2 different answers...
Oldest man alive
The oldest living man since the death of Henry Allingham, on 18 July 2009, is 113-year old Walter Breuning, who is from the United States born 21 September 1896.
Henry Allingham - 114 years 42 days
Walter Breuning - 113 years 101 days and living
A centenarian is a person who has attained the age of 100 years or more, but once they reach 110 they become a supercentenarian. So the oldest centenarian cannot be older than 109 years 364 days 23 hours 59 minutes and 59 seconds !
In both centenarians and supercentenarians the person does not need to be alive to be included in the definition, hence the oldest supercentenarian is the oldest person to have lived. The oldest CONFIRMED, DOCUMENTED and VERIFIED person of all time is
Jeanne Calment 122 years 164 days (a woman).