2161404165 has 16 divisors (see below), whose sum is σ = 3569803776. Its totient is φ = 1115563200.

The previous prime is 2161404163. The next prime is 2161404187. The reversal of 2161404165 is 5614041612.

It is not a de Polignac number, because 2161404165 - 2¹ = 2161404163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161404163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2323626 + ... + 2324555.

It is an arithmetic number, because the mean of its divisors is an integer number (223112736).

Almost surely, 2^2161404165 is an apocalyptic number.

It is an amenable number.

2161404165 is a deficient number, since it is larger than the sum of its proper divisors (1408399611).

2161404165 is a wasteful number, since it uses less digits than its factorization.

2161404165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4648220.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 2161404165 is about 46490.9041103741. The cubic root of 2161404165 is about 1292.9408627682.

Adding to 2161404165 its reverse (5614041612), we get a palindrome (7775445777).

The spelling of 2161404165 in words is "two billion, one hundred sixty-one million, four hundred four thousand, one hundred sixty-five".