9664418921 has 4 divisors (see below), whose sum is σ = 10084611072. Its totient is φ = 9244226772.

The previous prime is 9664418909. The next prime is 9664418957. The reversal of 9664418921 is 1298144669.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 9664418921 - 2¹⁰ = 9664417897 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9664418921.

It is not an unprimeable number, because it can be changed into a prime (9664418221) 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, 210096041 + ... + 210096086.

It is an arithmetic number, because the mean of its divisors is an integer number (2521152768).

Almost surely, 2^9664418921 is an apocalyptic number.

It is an amenable number.

9664418921 is a deficient number, since it is larger than the sum of its proper divisors (420192151).

9664418921 is a wasteful number, since it uses less digits than its factorization.

9664418921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420192150.

The product of its digits is 746496, while the sum is 50.

The square root of 9664418921 is about 98307.7765031841. The cubic root of 9664418921 is about 2130.0603861446.

The spelling of 9664418921 in words is "nine billion, six hundred sixty-four million, four hundred eighteen thousand, nine hundred twenty-one".