2161644 has 12 divisors (see below), whose sum is σ = 5043864. Its totient is φ = 720544.

The previous prime is 2161639. The next prime is 2161697. The reversal of 2161644 is 4461612.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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, 90057 + ... + 90080.

It is an arithmetic number, because the mean of its divisors is an integer number (420322).

2^2161644 is an apocalyptic number.

It is an amenable number.

2161644 is an abundant number, since it is smaller than the sum of its proper divisors (2882220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2161644 is a wasteful number, since it uses less digits than its factorization.

2161644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180144 (or 180142 counting only the distinct ones).

The product of its digits is 1152, while the sum is 24.

The square root of 2161644 is about 1470.2530394459. The cubic root of 2161644 is about 129.2988683688.

Subtracting 2161644 from its reverse (4461612), we obtain a cube (2299968 = 132³).

The spelling of 2161644 in words is "two million, one hundred sixty-one thousand, six hundred forty-four".