Whether a mathematician can be called a scientist or not is a somewhat grey area which is not definitive. Strictly speaking, mathematicians are not considered natural scientists. The latter investigate the physical world; mathematicians’ work is more abstract and intangible.
Nevertheless, some of the traits one may find in a scientist – an investigative spirit, an enthusiasm for discovery, a voracious appetite for constant learning – can be found in a mathematician.
The general population, not involved in either science or mathematics, tend to categorize both in the one field. However, the majority of mathematicians would not consider themselves as scientists. Conversely, scientists would not label themselves mathematicians.
Mathematicians deal in absolute truths and must emerge with proof for a theory or hypothesis to be confirmed, while scientists can hypothesize and conditionally accept the results of the hypothesis. This is why mathematicians’ work is almost never redacted at a later date but sometimes scientists’ work can be revised or disproven.