2086891 has 4 divisors (see below), whose sum is σ = 2089800. Its totient is φ = 2083984.

The previous prime is 2086879. The next prime is 2086901. The reversal of 2086891 is 1986802.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1986802 = 2 ⋅993401.

It is a cyclic number.

It is not a de Polignac number, because 2086891 - 2¹⁷ = 1955819 is a prime.

It is a super-2 number, since 2×2086891² = 8710228091762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2086831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480 + ... + 2098.

It is an arithmetic number, because the mean of its divisors is an integer number (522450).

2^2086891 is an apocalyptic number.

2086891 is a deficient number, since it is larger than the sum of its proper divisors (2909).

2086891 is a wasteful number, since it uses less digits than its factorization.

2086891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2908.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 2086891 is about 1444.6075591662. The cubic root of 2086891 is about 127.7908980156.

The spelling of 2086891 in words is "two million, eighty-six thousand, eight hundred ninety-one".