2806389 has 6 divisors (see below), whose sum is σ = 4053686. Its totient is φ = 1870920.

The previous prime is 2806387. The next prime is 2806439. The reversal of 2806389 is 9836082.

It can be written as a sum of positive squares in only one way, i.e., 2125764 + 680625 = 1458^2 + 825^2 .

It is not a de Polignac number, because 2806389 - 2¹ = 2806387 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 (2806381) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 155902 + ... + 155919.

2^2806389 is an apocalyptic number.

It is an amenable number.

2806389 is a deficient number, since it is larger than the sum of its proper divisors (1247297).

2806389 is a wasteful number, since it uses less digits than its factorization.

2806389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311827 (or 311824 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 2806389 is about 1675.2280441779. The cubic root of 2806389 is about 141.0530960437.

The spelling of 2806389 in words is "two million, eight hundred six thousand, three hundred eighty-nine".