7728257664 has 288 divisors, whose sum is σ = 23936421600. Its totient is φ = 2392694784.

The previous prime is 7728257653. The next prime is 7728257671. The reversal of 7728257664 is 4667528277.

7728257664 is a `hidden beast` number, since 7 + 7 + 2 + 8 + 2 + 576 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

Its product of digits (7902720) is a multiple of the sum of its prime factors (360).

It is a self number, because there is not a number n which added to its sum of digits gives 7728257664.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 46276909 + ... + 46277075.

It is an arithmetic number, because the mean of its divisors is an integer number (83112575).

Almost surely, 2^7728257664 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 7728257664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11968210800).

7728257664 is an abundant number, since it is smaller than the sum of its proper divisors (16208163936).

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

7728257664 is a wasteful number, since it uses less digits than its factorization.

7728257664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360 (or 328 counting only the distinct ones).

The product of its digits is 7902720, while the sum is 54.

The square root of 7728257664 is about 87910.5094058725. The cubic root of 7728257664 is about 1977.0934519698.

The spelling of 7728257664 in words is "seven billion, seven hundred twenty-eight million, two hundred fifty-seven thousand, six hundred sixty-four".