2161565615 has 16 divisors (see below), whose sum is σ = 2834437536. Its totient is φ = 1569408000.

The previous prime is 2161565611. The next prime is 2161565687. The reversal of 2161565615 is 5165651612.

It is a happy number.

It is not a de Polignac number, because 2161565615 - 2² = 2161565611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161565611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 359 + ... + 65751.

It is an arithmetic number, because the mean of its divisors is an integer number (177152346).

Almost surely, 2^2161565615 is an apocalyptic number.

2161565615 is a deficient number, since it is larger than the sum of its proper divisors (672871921).

2161565615 is a wasteful number, since it uses less digits than its factorization.

2161565615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66010.

The product of its digits is 54000, while the sum is 38.

The square root of 2161565615 is about 46492.6404391061. The cubic root of 2161565615 is about 1292.9730548201.

The spelling of 2161565615 in words is "two billion, one hundred sixty-one million, five hundred sixty-five thousand, six hundred fifteen".