9664591121928 has 96 divisors (see below), whose sum is σ = 26368086850560. Its totient is φ = 3197761493760.

The previous prime is 9664591121897. The next prime is 9664591121929. The reversal of 9664591121928 is 8291211954669.

9664591121928 is a `hidden beast` number, since 9 + 6 + 6 + 4 + 591 + 1 + 2 + 19 + 28 = 666.

It is not an unprimeable number, because it can be changed into a prime (9664591121929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 155731401 + ... + 155793447.

It is an arithmetic number, because the mean of its divisors is an integer number (274667571360).

Almost surely, 2^{9664591121928} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9664591121928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13184043425280).

9664591121928 is an abundant number, since it is smaller than the sum of its proper divisors (16703495728632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9664591121928 is a wasteful number, since it uses less digits than its factorization.

9664591121928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77987 (or 77980 counting only the distinct ones).

The product of its digits is 16796160, while the sum is 63.

The spelling of 9664591121928 in words is "nine trillion, six hundred sixty-four billion, five hundred ninety-one million, one hundred twenty-one thousand, nine hundred twenty-eight".