8659664640 has 432 divisors, whose sum is σ = 33909273216. Its totient is φ = 2098483200.

The previous prime is 8659664633. The next prime is 8659664659. The reversal of 8659664640 is 464669568.

8659664640 is a `hidden beast` number, since 8 + 6 + 596 + 6 + 4 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3420175 + ... + 3422705.

It is an arithmetic number, because the mean of its divisors is an integer number (78493688).

Almost surely, 2^8659664640 is an apocalyptic number.

8659664640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8659664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16954636608).

8659664640 is an abundant number, since it is smaller than the sum of its proper divisors (25249608576).

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

8659664640 is a wasteful number, since it uses less digits than its factorization.

8659664640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2578 (or 2552 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The square root of 8659664640 is about 93057.3191103204. The cubic root of 8659664640 is about 2053.5267185415.

The spelling of 8659664640 in words is "eight billion, six hundred fifty-nine million, six hundred sixty-four thousand, six hundred forty".