2161161 has 10 divisors (see below), whose sum is σ = 3228522. Its totient is φ = 1440720.

The previous prime is 2161157. The next prime is 2161163. The reversal of 2161161 is 1611612.

It can be written as a sum of positive squares in only one way, i.e., 1089936 + 1071225 = 1044^2 + 1035^2 .

It is not a de Polignac number, because 2161161 - 2² = 2161157 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161163) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 13260 + ... + 13421.

2^2161161 is an apocalyptic number.

It is an amenable number.

2161161 is a deficient number, since it is larger than the sum of its proper divisors (1067361).

2161161 is an equidigital number, since it uses as much as digits as its factorization.

2161161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26693 (or 26684 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The square root of 2161161 is about 1470.0887728297. The cubic root of 2161161 is about 129.2892374265.

Adding to 2161161 its reverse (1611612), we get a palindrome (3772773).

The spelling of 2161161 in words is "two million, one hundred sixty-one thousand, one hundred sixty-one".