660663664 has 20 divisors (see below), whose sum is σ = 1289249080. Its totient is φ = 327954240.

The previous prime is 660663629. The next prime is 660663671. The reversal of 660663664 is 466366066.

660663664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 660663664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146307 + ... + 150754.

It is an arithmetic number, because the mean of its divisors is an integer number (64462454).

Almost surely, 2^660663664 is an apocalyptic number.

It is an amenable number.

660663664 is a deficient number, since it is larger than the sum of its proper divisors (628585416).

660663664 is a wasteful number, since it uses less digits than its factorization.

660663664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297208 (or 297202 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 43.

The square root of 660663664 is about 25703.3784549814. The cubic root of 660663664 is about 870.9505021032.

The spelling of 660663664 in words is "six hundred sixty million, six hundred sixty-three thousand, six hundred sixty-four".