2165986109 has 16 divisors (see below), whose sum is σ = 2518576896. Its totient is φ = 1824249600.

The previous prime is 2165986079. The next prime is 2165986157. The reversal of 2165986109 is 9016895612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2165986109 - 2¹⁶ = 2165920573 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165986169) 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, 551864 + ... + 555774.

It is an arithmetic number, because the mean of its divisors is an integer number (157411056).

Almost surely, 2^2165986109 is an apocalyptic number.

It is an amenable number.

2165986109 is a deficient number, since it is larger than the sum of its proper divisors (352590787).

2165986109 is a wasteful number, since it uses less digits than its factorization.

2165986109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5276.

The product of its (nonzero) digits is 233280, while the sum is 47.

The square root of 2165986109 is about 46540.1558764042. The cubic root of 2165986109 is about 1293.8538497110.

The spelling of 2165986109 in words is "two billion, one hundred sixty-five million, nine hundred eighty-six thousand, one hundred nine".