2165660215 has 4 divisors (see below), whose sum is σ = 2598792264. Its totient is φ = 1732528168.

The previous prime is 2165660201. The next prime is 2165660239. The reversal of 2165660215 is 5120665612.

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

It is a cyclic number.

It is not a de Polignac number, because 2165660215 - 2⁹ = 2165659703 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 216566017 + ... + 216566026.

It is an arithmetic number, because the mean of its divisors is an integer number (649698066).

Almost surely, 2^2165660215 is an apocalyptic number.

2165660215 is a deficient number, since it is larger than the sum of its proper divisors (433132049).

2165660215 is an equidigital number, since it uses as much as digits as its factorization.

2165660215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433132048.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 2165660215 is about 46536.6545316700. The cubic root of 2165660215 is about 1293.7889554266.

The spelling of 2165660215 in words is "two billion, one hundred sixty-five million, six hundred sixty thousand, two hundred fifteen".