2157990 has 16 divisors (see below), whose sum is σ = 5179248. Its totient is φ = 575456.

The previous prime is 2157989. The next prime is 2158019. The reversal of 2157990 is 997512.

2157990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

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, 35937 + ... + 35996.

It is an arithmetic number, because the mean of its divisors is an integer number (323703).

2^2157990 is an apocalyptic number.

2157990 is an abundant number, since it is smaller than the sum of its proper divisors (3021258).

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

2157990 is a wasteful number, since it uses less digits than its factorization.

2157990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71943.

The product of its (nonzero) digits is 5670, while the sum is 33.

The square root of 2157990 is about 1469.0098706272. The cubic root of 2157990 is about 129.2259725348.

The spelling of 2157990 in words is "two million, one hundred fifty-seven thousand, nine hundred ninety".