9921660008 has 64 divisors (see below), whose sum is σ = 21125529600. Its totient is φ = 4330609920.

The previous prime is 9921659977. The next prime is 9921660041. The reversal of 9921660008 is 8000661299.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1207193 + ... + 1215383.

It is an arithmetic number, because the mean of its divisors is an integer number (330086400).

Almost surely, 2^9921660008 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 9921660008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10562764800).

9921660008 is an abundant number, since it is smaller than the sum of its proper divisors (11203869592).

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

9921660008 is a wasteful number, since it uses less digits than its factorization.

9921660008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8842 (or 8838 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 9921660008 is about 99607.5298760089. The cubic root of 9921660008 is about 2148.7939879903.

The spelling of 9921660008 in words is "nine billion, nine hundred twenty-one million, six hundred sixty thousand, eight".