9988891 has 4 divisors (see below), whose sum is σ = 10896984. Its totient is φ = 9080800.

The previous prime is 9988879. The next prime is 9988907. The reversal of 9988891 is 1988899.

9988891 is digitally balanced in base 2, 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 a cyclic number.

It is not a de Polignac number, because 9988891 - 2¹³ = 9980699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9988291) 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, 454030 + ... + 454051.

It is an arithmetic number, because the mean of its divisors is an integer number (2724246).

Almost surely, 2^9988891 is an apocalyptic number.

9988891 is a deficient number, since it is larger than the sum of its proper divisors (908093).

9988891 is a wasteful number, since it uses less digits than its factorization.

9988891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908092.

The product of its digits is 373248, while the sum is 52.

The square root of 9988891 is about 3160.5206849505. The cubic root of 9988891 is about 215.3636607263.

It can be divided in two parts, 998 and 8891, that added together give a palindrome (9889).

The spelling of 9988891 in words is "nine million, nine hundred eighty-eight thousand, eight hundred ninety-one".