2156911 has 4 divisors (see below), whose sum is σ = 2159872. Its totient is φ = 2153952.

The previous prime is 2156897. The next prime is 2156939. The reversal of 2156911 is 1196512.

2156911 is nontrivially palindromic in base 6.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2156911 - 2⁵ = 2156879 is a prime.

It is a Duffinian number.

2156911 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156111) 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, 466 + ... + 2128.

It is an arithmetic number, because the mean of its divisors is an integer number (539968).

2^2156911 is an apocalyptic number.

2156911 is a deficient number, since it is larger than the sum of its proper divisors (2961).

2156911 is a wasteful number, since it uses less digits than its factorization.

2156911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2960.

The product of its digits is 540, while the sum is 25.

The square root of 2156911 is about 1468.6425705392. The cubic root of 2156911 is about 129.2044311822.

The spelling of 2156911 in words is "two million, one hundred fifty-six thousand, nine hundred eleven".