2155120111 has 4 divisors (see below), whose sum is σ = 2156809032. Its totient is φ = 2153431192.

The previous prime is 2155120091. The next prime is 2155120129. The reversal of 2155120111 is 1110215512.

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 2155120111 - 2⁹ = 2155119599 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 (2155120151) 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, 842545 + ... + 845098.

It is an arithmetic number, because the mean of its divisors is an integer number (539202258).

Almost surely, 2^2155120111 is an apocalyptic number.

2155120111 is a deficient number, since it is larger than the sum of its proper divisors (1688921).

2155120111 is a wasteful number, since it uses less digits than its factorization.

2155120111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688920.

The product of its (nonzero) digits is 100, while the sum is 19.

The square root of 2155120111 is about 46423.2712225237. The cubic root of 2155120111 is about 1291.6866168508.

Adding to 2155120111 its reverse (1110215512), we get a palindrome (3265335623).

The spelling of 2155120111 in words is "two billion, one hundred fifty-five million, one hundred twenty thousand, one hundred eleven".