891113145921 has 6 divisors (see below), whose sum is σ = 1287163433010. Its totient is φ = 594075430608.

The previous prime is 891113145913. The next prime is 891113145971. The reversal of 891113145921 is 129541311198.

891113145921 is a `hidden beast` number, since 89 + 1 + 113 + 1 + 459 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 641178141696 + 249935004225 = 800736^2 + 499935^2 .

It is not a de Polignac number, because 891113145921 - 2³ = 891113145913 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (891113145971) 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, 49506285876 + ... + 49506285893.

It is an arithmetic number, because the mean of its divisors is an integer number (214527238835).

Almost surely, 2^891113145921 is an apocalyptic number.

It is an amenable number.

891113145921 is a deficient number, since it is larger than the sum of its proper divisors (396050287089).

891113145921 is a wasteful number, since it uses less digits than its factorization.

891113145921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99012571775 (or 99012571772 counting only the distinct ones).

The product of its digits is 77760, while the sum is 45.

The spelling of 891113145921 in words is "eight hundred ninety-one billion, one hundred thirteen million, one hundred forty-five thousand, nine hundred twenty-one".