9721568890 has 16 divisors (see below), whose sum is σ = 19089626400. Its totient is φ = 3535115920.

The previous prime is 9721568887. The next prime is 9721568893. The reversal of 9721568890 is 988651279.

It is an interprime number because it is at equal distance from previous prime (9721568887) and next prime (9721568893).

It is a Harshad number since it is a multiple of its sum of digits (55).

It is not an unprimeable number, because it can be changed into a prime (9721568893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44188840 + ... + 44189059.

It is an arithmetic number, because the mean of its divisors is an integer number (1193101650).

Almost surely, 2^9721568890 is an apocalyptic number.

9721568890 is a deficient number, since it is larger than the sum of its proper divisors (9368057510).

9721568890 is a wasteful number, since it uses less digits than its factorization.

9721568890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88377917.

The product of its (nonzero) digits is 2177280, while the sum is 55.

The square root of 9721568890 is about 98598.0166636226. The cubic root of 9721568890 is about 2134.2507990340.

The spelling of 9721568890 in words is "nine billion, seven hundred twenty-one million, five hundred sixty-eight thousand, eight hundred ninety".