2011105991 has 4 divisors (see below), whose sum is σ = 2022341400. Its totient is φ = 1999870584.

The previous prime is 2011105963. The next prime is 2011106107. The reversal of 2011105991 is 1995011102.

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

It is a cyclic number.

It is not a de Polignac number, because 2011105991 - 2⁶ = 2011105927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2011105931) 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, 5617436 + ... + 5617793.

It is an arithmetic number, because the mean of its divisors is an integer number (505585350).

Almost surely, 2^2011105991 is an apocalyptic number.

2011105991 is a deficient number, since it is larger than the sum of its proper divisors (11235409).

2011105991 is a wasteful number, since it uses less digits than its factorization.

2011105991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11235408.

The product of its (nonzero) digits is 810, while the sum is 29.

The square root of 2011105991 is about 44845.3564039801. The cubic root of 2011105991 is about 1262.2488584006.

The spelling of 2011105991 in words is "two billion, eleven million, one hundred five thousand, nine hundred ninety-one".