8664520643 has 4 divisors (see below), whose sum is σ = 8665291368. Its totient is φ = 8663749920.

The previous prime is 8664520639. The next prime is 8664520651. The reversal of 8664520643 is 3460254668.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8664520643 - 2² = 8664520639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8664520594 and 8664520603.

It is not an unprimeable number, because it can be changed into a prime (8664520663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 368246 + ... + 391067.

It is an arithmetic number, because the mean of its divisors is an integer number (2166322842).

Almost surely, 2^8664520643 is an apocalyptic number.

8664520643 is a deficient number, since it is larger than the sum of its proper divisors (770725).

8664520643 is a wasteful number, since it uses less digits than its factorization.

8664520643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770724.

The product of its (nonzero) digits is 829440, while the sum is 44.

The square root of 8664520643 is about 93083.4069155185. The cubic root of 8664520643 is about 2053.9104927769.

The spelling of 8664520643 in words is "eight billion, six hundred sixty-four million, five hundred twenty thousand, six hundred forty-three".