945 is the smallest odd-abundant number. 945 = 33*5*7, so the sum of all divisors of 945 (including itself) is (1+3+32+33)*(1+5)*(1+7) = 40*6*8 = 1920, while 945*2=1890<1920. Therefore, 945 is an abundant number. By trial and error we can check it is also smallest odd number with this property.