2181641 has 16 divisors (see below), whose sum is σ = 2816640. Its totient is φ = 1639680.

The previous prime is 2181629. The next prime is 2181649. The reversal of 2181641 is 1461812.

It is not a de Polignac number, because 2181641 - 2⁶ = 2181577 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 (2181649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1745 + ... + 2721.

It is an arithmetic number, because the mean of its divisors is an integer number (176040).

2^2181641 is an apocalyptic number.

It is an amenable number.

2181641 is a deficient number, since it is larger than the sum of its proper divisors (634999).

2181641 is a wasteful number, since it uses less digits than its factorization.

2181641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1024.

The product of its digits is 384, while the sum is 23.

The square root of 2181641 is about 1477.0379142053. The cubic root of 2181641 is about 129.6963524513.

The spelling of 2181641 in words is "two million, one hundred eighty-one thousand, six hundred forty-one".