9889727021 has 4 divisors (see below), whose sum is σ = 9890397792. Its totient is φ = 9889056252.

The previous prime is 9889727017. The next prime is 9889727041. The reversal of 9889727021 is 1207279889.

It is a happy number.

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 9889727021 - 2² = 9889727017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9889727011) 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, 312761 + ... + 342926.

It is an arithmetic number, because the mean of its divisors is an integer number (2472599448).

Almost surely, 2^9889727021 is an apocalyptic number.

It is an amenable number.

9889727021 is a deficient number, since it is larger than the sum of its proper divisors (670771).

9889727021 is a wasteful number, since it uses less digits than its factorization.

9889727021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670770.

The product of its (nonzero) digits is 1016064, while the sum is 53.

The square root of 9889727021 is about 99447.1066497161. The cubic root of 9889727021 is about 2146.4862035512.

The spelling of 9889727021 in words is "nine billion, eight hundred eighty-nine million, seven hundred twenty-seven thousand, twenty-one".