2161990 has 16 divisors (see below), whose sum is σ = 3920400. Its totient is φ = 858400.

The previous prime is 2161987. The next prime is 2162003. The reversal of 2161990 is 991612.

2161990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 765 + ... + 2215.

It is an arithmetic number, because the mean of its divisors is an integer number (245025).

2^2161990 is an apocalyptic number.

2161990 is a deficient number, since it is larger than the sum of its proper divisors (1758410).

2161990 is a wasteful number, since it uses less digits than its factorization.

2161990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1607.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 2161990 is about 1470.3707015579. The cubic root of 2161990 is about 129.3057666711.

The spelling of 2161990 in words is "two million, one hundred sixty-one thousand, nine hundred ninety".