9898558991 has 16 divisors (see below), whose sum is σ = 10466607360. Its totient is φ = 9361252728.

The previous prime is 9898558981. The next prime is 9898559017. The reversal of 9898558991 is 1998558989.

It is not a de Polignac number, because 9898558991 - 2⁶ = 9898558927 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 (9898558931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6083120 + ... + 6084746.

It is an arithmetic number, because the mean of its divisors is an integer number (654162960).

Almost surely, 2^9898558991 is an apocalyptic number.

9898558991 is a deficient number, since it is larger than the sum of its proper divisors (568048369).

9898558991 is an equidigital number, since it uses as much as digits as its factorization.

9898558991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2571 (or 2533 counting only the distinct ones).

The product of its digits is 83980800, while the sum is 71.

The square root of 9898558991 is about 99491.5021044511. The cubic root of 9898558991 is about 2147.1249829349.

The spelling of 9898558991 in words is "nine billion, eight hundred ninety-eight million, five hundred fifty-eight thousand, nine hundred ninety-one".