2157181111 has 8 divisors (see below), whose sum is σ = 2191125104. Its totient is φ = 2123288640.

The previous prime is 2157181087. The next prime is 2157181123. The reversal of 2157181111 is 1111817512.

2157181111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2157181111 - 2⁵ = 2157181079 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2157181111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157181181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76321 + ... + 100693.

It is an arithmetic number, because the mean of its divisors is an integer number (273890638).

Almost surely, 2^2157181111 is an apocalyptic number.

2157181111 is a deficient number, since it is larger than the sum of its proper divisors (33943993).

2157181111 is a wasteful number, since it uses less digits than its factorization.

2157181111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25761.

The product of its digits is 560, while the sum is 28.

The square root of 2157181111 is about 46445.4638366332. The cubic root of 2157181111 is about 1292.0982440142.

Adding to 2157181111 its reverse (1111817512), we get a palindrome (3268998623).

The spelling of 2157181111 in words is "two billion, one hundred fifty-seven million, one hundred eighty-one thousand, one hundred eleven".