2157169887 has 20 divisors (see below), whose sum is σ = 3250969920. Its totient is φ = 1425380544.

The previous prime is 2157169879. The next prime is 2157169913. The reversal of 2157169887 is 7889617512.

2157169887 is a `hidden beast` number, since 2 + 1 + 571 + 69 + 8 + 8 + 7 = 666.

2157169887 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2157169887 - 2³ = 2157169879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157169837) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 108687 + ... + 126992.

It is an arithmetic number, because the mean of its divisors is an integer number (162548496).

Almost surely, 2^2157169887 is an apocalyptic number.

2157169887 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

2157169887 is a deficient number, since it is larger than the sum of its proper divisors (1093800033).

2157169887 is a wasteful number, since it uses less digits than its factorization.

2157169887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235804 (or 235795 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 54.

The square root of 2157169887 is about 46445.3430065922. The cubic root of 2157169887 is about 1292.0960030440.

The spelling of 2157169887 in words is "two billion, one hundred fifty-seven million, one hundred sixty-nine thousand, eight hundred eighty-seven".