 Only 58 stable nuclides have an odd neutron number, compared to 194 with an even neutron number.No odd-neutron-number isotope is the most naturally abundant isotope in its element, except for beryllium-9 (which is the only stable beryllium isotope), nitrogen-14, and platinum-195.No stable nuclides have neutron number 19, 21, 35, 39, 45, 61, 89, 115, 123, and ≥ 127.