91123201121 has 4 divisors (see below), whose sum is σ = 94265380500. Its totient is φ = 87981021744.

The previous prime is 91123201097. The next prime is 91123201163. The reversal of 91123201121 is 12110232119.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24075866896 + 67047334225 = 155164^2 + 258935^2 .

It is a de Polignac number, because none of the positive numbers 2^k-91123201121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91123201171) 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, 1571089646 + ... + 1571089703.

It is an arithmetic number, because the mean of its divisors is an integer number (23566345125).

Almost surely, 2^91123201121 is an apocalyptic number.

It is an amenable number.

91123201121 is a deficient number, since it is larger than the sum of its proper divisors (3142179379).

91123201121 is a wasteful number, since it uses less digits than its factorization.

91123201121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3142179378.

The product of its (nonzero) digits is 216, while the sum is 23.

The spelling of 91123201121 in words is "ninety-one billion, one hundred twenty-three million, two hundred one thousand, one hundred twenty-one".