Naturally-occurring scandium (21Sc) is composed of one stable isotope, 45Sc. Twenty-six radioisotopes have been characterized from 37Sc to 63Sc, with the most stable being 46Sc with a half-life of 83.76 days, 47Sc with a half-life of 3.3492 days, 48Sc at 43.67 hours, 44Sc at 4.042 hours, and 43Sc at 3.891 hours. All other radioisotopes isotopes have half-lives shorter than an hour, and the majority of these shorter than 15 seconds. This element also has 13 meta states with the most stable being 44m3Sc ; this is the lightest isotope with a long-lived isomer.