2165765771 has 4 divisors (see below), whose sum is σ = 2332363152. Its totient is φ = 1999168392.

The previous prime is 2165765761. The next prime is 2165765843. The reversal of 2165765771 is 1775675612.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 2165765771 - 2²⁶ = 2098656907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2165765731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83298671 + ... + 83298696.

It is an arithmetic number, because the mean of its divisors is an integer number (583090788).

Almost surely, 2^2165765771 is an apocalyptic number.

2165765771 is a deficient number, since it is larger than the sum of its proper divisors (166597381).

2165765771 is a wasteful number, since it uses less digits than its factorization.

2165765771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166597380.

The product of its digits is 617400, while the sum is 47.

The square root of 2165765771 is about 46537.7886346139. The cubic root of 2165765771 is about 1293.8099751857.

The spelling of 2165765771 in words is "two billion, one hundred sixty-five million, seven hundred sixty-five thousand, seven hundred seventy-one".