2809864 has 16 divisors (see below), whose sum is σ = 5497920. Its totient is φ = 1343760.

The previous prime is 2809847. The next prime is 2809867. The reversal of 2809864 is 4689082.

It is not an unprimeable number, because it can be changed into a prime (2809867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7452 + ... + 7819.

It is an arithmetic number, because the mean of its divisors is an integer number (343620).

2^2809864 is an apocalyptic number.

It is an amenable number.

2809864 is a deficient number, since it is larger than the sum of its proper divisors (2688056).

2809864 is a wasteful number, since it uses less digits than its factorization.

2809864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15300 (or 15296 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 2809864 is about 1676.2648955341. The cubic root of 2809864 is about 141.1112915083. Note that the first 3 decimals are identical.

The spelling of 2809864 in words is "two million, eight hundred nine thousand, eight hundred sixty-four".