OCaml uses a tag bit to distinguish ints from pointers, so (unboxed) ints are only 31 bits:<p><a href="https:&#x2F;&#x2F;realworldocaml.org&#x2F;v1&#x2F;en&#x2F;html&#x2F;memory-representation-of-values.html" rel="nofollow">https:&#x2F;&#x2F;realworldocaml.org&#x2F;v1&#x2F;en&#x2F;html&#x2F;memory-representation-...</a><p>Floating point numbers are normally boxed (except for float arrays, float-only records, and some cases of local use).