9806538891 has 4 divisors (see below), whose sum is σ = 13075385192. Its totient is φ = 6537692592.

The previous prime is 9806538881. The next prime is 9806538899. The reversal of 9806538891 is 1988356089.

9806538891 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 9806538891 - 2⁶ = 9806538827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9806538899) 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, 1634423146 + ... + 1634423151.

It is an arithmetic number, because the mean of its divisors is an integer number (3268846298).

Almost surely, 2^9806538891 is an apocalyptic number.

9806538891 is a deficient number, since it is larger than the sum of its proper divisors (3268846301).

9806538891 is a wasteful number, since it uses less digits than its factorization.

9806538891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3268846300.

The product of its (nonzero) digits is 3732480, while the sum is 57.

The square root of 9806538891 is about 99027.9702457846. The cubic root of 9806538891 is about 2140.4508098360.

The spelling of 9806538891 in words is "nine billion, eight hundred six million, five hundred thirty-eight thousand, eight hundred ninety-one".