A memory has an array of k-level cells, organized into pages of words, each storing a string of bits. The memory device includes a coding circuit input with strings of N bits, and generates corresponding k-level strings. A program circuit is input with the k-level strings to stores in groups of c cells with k levels. A read circuit reads data stored in groups of c cells with k levels and generates k-level strings. A read decoding circuit is input with k-level strings read from groups of c cells with k levels to generate strings of N bits. The words of each page are grouped in groups of words, each word including groups of c cells with k levels, and at least one remaining bit of the word being stored, with corresponding remaining bits of other words of the page, in a group of c cells with k levels.