A la recherche du temps perdu by Marcel Proust contains an estimated 9,609,000 characters (each letter counts as one character. Spaces are also counted, as one character each).
The title translates to "Remembrance of Things Past".
Proust produced the first volume of his 13-volume masterpiece in 1912 (it was first published in 1913).
The second part of his work won international awards as soon as it was published and with them, an international reputation.