9998891 has 6 divisors (see below), whose sum is σ = 11631420. Its totient is φ = 8570436.

The previous prime is 9998887. The next prime is 9998893. The reversal of 9998891 is 1988999.

It is not a de Polignac number, because 9998891 - 2² = 9998887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9998893) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101981 + ... + 102078.

It is an arithmetic number, because the mean of its divisors is an integer number (1938570).

Almost surely, 2^9998891 is an apocalyptic number.

9998891 is a deficient number, since it is larger than the sum of its proper divisors (1632529).

9998891 is a wasteful number, since it uses less digits than its factorization.

9998891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204073 (or 204066 counting only the distinct ones).

The product of its digits is 419904, while the sum is 53.

The square root of 9998891 is about 3162.1023070103. The cubic root of 9998891 is about 215.4355044819.

The spelling of 9998891 in words is "nine million, nine hundred ninety-eight thousand, eight hundred ninety-one".