9191311121 has 4 divisors (see below), whose sum is σ = 9198399012. Its totient is φ = 9184223232.

The previous prime is 9191311109. The next prime is 9191311247. The reversal of 9191311121 is 1211131919.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1211131919 = 9923 ⋅122053.

It can be written as a sum of positive squares in 2 ways, for example, as 5761569025 + 3429742096 = 75905^2 + 58564^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9191311121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9191311321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3542000 + ... + 3544593.

It is an arithmetic number, because the mean of its divisors is an integer number (2299599753).

Almost surely, 2^9191311121 is an apocalyptic number.

It is an amenable number.

9191311121 is a deficient number, since it is larger than the sum of its proper divisors (7087891).

9191311121 is a wasteful number, since it uses less digits than its factorization.

9191311121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7087890.

The product of its digits is 486, while the sum is 29.

The square root of 9191311121 is about 95871.3258539799. The cubic root of 9191311121 is about 2094.7192429306.

The spelling of 9191311121 in words is "nine billion, one hundred ninety-one million, three hundred eleven thousand, one hundred twenty-one".