2085990891 has 4 divisors (see below), whose sum is σ = 2781321192. Its totient is φ = 1390660592.

The previous prime is 2085990889. The next prime is 2085990941. The reversal of 2085990891 is 1980995802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2085990891 - 2¹ = 2085990889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2085994891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 347665146 + ... + 347665151.

It is an arithmetic number, because the mean of its divisors is an integer number (695330298).

Almost surely, 2^2085990891 is an apocalyptic number.

2085990891 is a deficient number, since it is larger than the sum of its proper divisors (695330301).

2085990891 is an equidigital number, since it uses as much as digits as its factorization.

2085990891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695330300.

The product of its (nonzero) digits is 466560, while the sum is 51.

The square root of 2085990891 is about 45672.6492662731. The cubic root of 2085990891 is about 1277.7252263031.

The spelling of 2085990891 in words is "two billion, eighty-five million, nine hundred ninety thousand, eight hundred ninety-one".