2165815489 has 4 divisors (see below), whose sum is σ = 2165914324. Its totient is φ = 2165716656.

The previous prime is 2165815481. The next prime is 2165815513. The reversal of 2165815489 is 9845185612.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2092147600 + 73667889 = 45740^2 + 8583^2 .

It is a cyclic number.

It is not a de Polignac number, because 2165815489 - 2³ = 2165815481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2165815481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222 + ... + 65815.

It is an arithmetic number, because the mean of its divisors is an integer number (541478581).

Almost surely, 2^2165815489 is an apocalyptic number.

It is an amenable number.

2165815489 is a deficient number, since it is larger than the sum of its proper divisors (98835).

2165815489 is an equidigital number, since it uses as much as digits as its factorization.

2165815489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98834.

The product of its digits is 691200, while the sum is 49.

The square root of 2165815489 is about 46538.3227996025. The cubic root of 2165815489 is about 1293.8198754795.

The spelling of 2165815489 in words is "two billion, one hundred sixty-five million, eight hundred fifteen thousand, four hundred eighty-nine".