8643209640 has 64 divisors (see below), whose sum is σ = 27924220800. Its totient is φ = 2127558912.

The previous prime is 8643209599. The next prime is 8643209647. The reversal of 8643209640 is 469023468.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 8643209592 and 8643209601.

It is not an unprimeable number, because it can be changed into a prime (8643209647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2768700 + ... + 2771819.

It is an arithmetic number, because the mean of its divisors is an integer number (436315950).

Almost surely, 2^8643209640 is an apocalyptic number.

It is an amenable number.

8643209640 is an abundant number, since it is smaller than the sum of its proper divisors (19281011160).

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

8643209640 is a wasteful number, since it uses less digits than its factorization.

8643209640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5540546 (or 5540542 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 8643209640 is about 92968.8638200984. The cubic root of 8643209640 is about 2052.2251974803.

The spelling of 8643209640 in words is "eight billion, six hundred forty-three million, two hundred nine thousand, six hundred forty".