long time no see; it's been a while
Polite greeting used when meeting someone after a long absence. Often used with ですね or です.
Long time no see. How have you been?
Tanaka-san, it's been a while.
お久しぶり adds the polite prefix お and is used with strangers or superiors, while 久しぶり is the plain, casual form used among friends.
Standard polite spelling; the most common written form.
Variant using 振り; less common but still seen.
Polite form of 久しぶり (ひさしぶり), with the honorific prefix お added. 久しぶり itself is a noun meaning 'a long time (since the last occurrence)'. The expression is a fixed greeting.