9991133121 has 16 divisors (see below), whose sum is σ = 14126776704. Its totient is φ = 6259325184.

The previous prime is 9991133111. The next prime is 9991133143. The reversal of 9991133121 is 1213311999.

It is not a de Polignac number, because 9991133121 - 2³⁰ = 8917391297 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9991133121.

It is not an unprimeable number, because it can be changed into a prime (9991133111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116701 + ... + 183306.

It is an arithmetic number, because the mean of its divisors is an integer number (882923544).

Almost surely, 2^9991133121 is an apocalyptic number.

It is an amenable number.

9991133121 is a deficient number, since it is larger than the sum of its proper divisors (4135643583).

9991133121 is a wasteful number, since it uses less digits than its factorization.

9991133121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300680.

The product of its digits is 13122, while the sum is 39.

The square root of 9991133121 is about 99955.6557729476. The cubic root of 9991133121 is about 2153.7977313433.

The spelling of 9991133121 in words is "nine billion, nine hundred ninety-one million, one hundred thirty-three thousand, one hundred twenty-one".