2166709687 has 16 divisors (see below), whose sum is σ = 2434510080. Its totient is φ = 1917511552.

The previous prime is 2166709607. The next prime is 2166709693. The reversal of 2166709687 is 7869076612.

It is a happy number.

2166709687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2166709687 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 (2166709607) 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, 23893 + ... + 70030.

It is an arithmetic number, because the mean of its divisors is an integer number (152156880).

Almost surely, 2^2166709687 is an apocalyptic number.

2166709687 is a deficient number, since it is larger than the sum of its proper divisors (267800393).

2166709687 is a wasteful number, since it uses less digits than its factorization.

2166709687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94022.

The product of its (nonzero) digits is 1524096, while the sum is 52.

The square root of 2166709687 is about 46547.9289227781. The cubic root of 2166709687 is about 1293.9979103378.

The spelling of 2166709687 in words is "two billion, one hundred sixty-six million, seven hundred nine thousand, six hundred eighty-seven".