This study pertains to stylometry. There are cases when a writer who has achieved fame, for various reasons, begins to create under a different name, attempts to write in a different manner and sometimes achieves success again in a new incarnation. The aim of the study is to test the feasibility of intentionally making significant changes to an author’s literary style. Numerals present in the texts by a particular author are used as a style marker. Examples from English, French and Russian literature demonstrate that the use of numerals is a literary ‘fingerprint’ that manifests in all or most of sufficiently long texts by that author. The obtained results show that, contrary to an author’s attempts to write in a ‘new’ way, the usage of numerals is conservative and allows for the recognition of fictitious authorship. This conclusion is drawn based on the analysis of works by R. Gary and B. Akunin (G. Chkhartishvili), who are known for their literary hoaxes. The analysis of numerals usage is also applied to the issue of authorship regarding Harper Lee’s novel ‘To Kill a Mockingbird’. Conclusions about the similarity/difference of literary styles are made based on hierarchical cluster analysis and are supported by the Pearson chi-squared test. The scientific originality of the paper lies in taking a new approach to the search for a literary ‘fingerprint’ and text attribution.