12112100991 has 28 divisors (see below), whose sum is σ = 18170661568. Its totient is φ = 8069925024.

The previous prime is 12112100989. The next prime is 12112100999. The reversal of 12112100991 is 19900121121.

It is not a de Polignac number, because 12112100991 - 2¹ = 12112100989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12112100999) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 1558371 + ... + 1566123.

Almost surely, 2^12112100991 is an apocalyptic number.

12112100991 is a deficient number, since it is larger than the sum of its proper divisors (6058560577).

12112100991 is an frugal number, since it uses more digits than its factorization.

12112100991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9914 (or 9899 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 27.

The spelling of 12112100991 in words is "twelve billion, one hundred twelve million, one hundred thousand, nine hundred ninety-one".