The total number of inflectional morphemes in the word "remarkably" is 1.
The inflectional morpheme is the prefix re-.
Inflectional morphemes don't change the grammatical category of the word, that is, it doesn't modify the type of the base word, which in this case is the infrequent adjective 'markable'. By adding the prefix re-, the word remains as an adjective.
The suffix -ly changes the base word 'markable' (or 'remarkable') from an adjective to an adverb; thus, the suffix -ly is a derivational morpheme. The suffix -ly can be counted as an inflectional morpheme only if and only if one considers adjectives and adverbs to share a grammatical category, which is a complex and by most linguists erroneous argument to make.
