2156111211111 has 16 divisors (see below), whose sum is σ = 3377404974720. Its totient is φ = 1206216061920.

The previous prime is 2156111211101. The next prime is 2156111211139. The reversal of 2156111211111 is 1111121116512.

It is not a de Polignac number, because 2156111211111 - 2¹⁹ = 2156110686823 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156111211101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2512949701 + ... + 2512950558.

It is an arithmetic number, because the mean of its divisors is an integer number (211087810920).

Almost surely, 2^{2156111211111} is an apocalyptic number.

2156111211111 is a deficient number, since it is larger than the sum of its proper divisors (1221293763609).

2156111211111 is a wasteful number, since it uses less digits than its factorization.

2156111211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5025900286.

The product of its digits is 120, while the sum is 24.

Adding to 2156111211111 its reverse (1111121116512), we get a palindrome (3267232327623).

The spelling of 2156111211111 in words is "two trillion, one hundred fifty-six billion, one hundred eleven million, two hundred eleven thousand, one hundred eleven".