65811664 has 20 divisors (see below), whose sum is σ = 127776420. Its totient is φ = 32837120.

The previous prime is 65811659. The next prime is 65811679. The reversal of 65811664 is 46611856.

65811664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 38688400 + 27123264 = 6220^2 + 5208^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4104 + ... + 12184.

It is an arithmetic number, because the mean of its divisors is an integer number (6388821).

Almost surely, 2^65811664 is an apocalyptic number.

It is an amenable number.

65811664 is a deficient number, since it is larger than the sum of its proper divisors (61964756).

65811664 is a wasteful number, since it uses less digits than its factorization.

65811664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8598 (or 8592 counting only the distinct ones).

The product of its digits is 34560, while the sum is 37.

The square root of 65811664 is about 8112.4388441455. The cubic root of 65811664 is about 403.7392363587.

The spelling of 65811664 in words is "sixty-five million, eight hundred eleven thousand, six hundred sixty-four".