2161641 has 4 divisors (see below), whose sum is σ = 2882192. Its totient is φ = 1441092.

The previous prime is 2161639. The next prime is 2161697. The reversal of 2161641 is 1461612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2161641 - 2¹ = 2161639 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2161141) 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, 360271 + ... + 360276.

It is an arithmetic number, because the mean of its divisors is an integer number (720548).

2^2161641 is an apocalyptic number.

It is an amenable number.

2161641 is a deficient number, since it is larger than the sum of its proper divisors (720551).

2161641 is an equidigital number, since it uses as much as digits as its factorization.

2161641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720550.

The product of its digits is 288, while the sum is 21.

The square root of 2161641 is about 1470.2520192130. The cubic root of 2161641 is about 129.2988085537.

The spelling of 2161641 in words is "two million, one hundred sixty-one thousand, six hundred forty-one".