65 (sixty-five) is the natural number following 64 and preceding 66.
In mathematics
65 is the nineteenth distinct semiprime, (5.13); and the third of the form (5.q), where q is a higher prime.
65 has a prime aliquot sum of 19 within an aliquot sequence of one composite numbers (65,19,1,0) to the prime; as the first member' of the 19-aliquot tree.