2165242209 has 16 divisors (see below), whose sum is σ = 3112741632. Its totient is φ = 1330881408.

The previous prime is 2165242181. The next prime is 2165242217. The reversal of 2165242209 is 9022425612.

It is not a de Polignac number, because 2165242209 - 2¹³ = 2165234017 is a prime.

It is a super-3 number, since 3×2165242209³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2165242209.

It is not an unprimeable number, because it can be changed into a prime (2165242229) 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, 1032 + ... + 65814.

It is an arithmetic number, because the mean of its divisors is an integer number (194546352).

Almost surely, 2^2165242209 is an apocalyptic number.

It is an amenable number.

2165242209 is a deficient number, since it is larger than the sum of its proper divisors (947499423).

2165242209 is a wasteful number, since it uses less digits than its factorization.

2165242209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65656.

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 2165242209 is about 46532.1631669967. The cubic root of 2165242209 is about 1293.7057096276.

It can be divided in two parts, 216 and 5242209, that added together give a palindrome (5242425).

The spelling of 2165242209 in words is "two billion, one hundred sixty-five million, two hundred forty-two thousand, two hundred nine".