991101101121 has 12 divisors (see below), whose sum is σ = 1431607177572. Its totient is φ = 660726360576.

The previous prime is 991101101099. The next prime is 991101101167. The reversal of 991101101121 is 121101101199.

It can be written as a sum of positive squares in 2 ways, for example, as 637819460496 + 353281640625 = 798636^2 + 594375^2 .

It is not a de Polignac number, because 991101101121 - 2¹⁰ = 991101100097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991101101621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235345 + ... + 1427441.

It is an arithmetic number, because the mean of its divisors is an integer number (119300598131).

Almost surely, 2^991101101121 is an apocalyptic number.

It is an amenable number.

991101101121 is a deficient number, since it is larger than the sum of its proper divisors (440506076451).

991101101121 is a wasteful number, since it uses less digits than its factorization.

991101101121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284480 (or 1284477 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 27.

The spelling of 991101101121 in words is "nine hundred ninety-one billion, one hundred one million, one hundred one thousand, one hundred twenty-one".