2809000821 has 16 divisors (see below), whose sum is σ = 4115220480. Its totient is φ = 1690174320.

The previous prime is 2809000819. The next prime is 2809000849. The reversal of 2809000821 is 1280009082.

It is not a de Polignac number, because 2809000821 - 2¹ = 2809000819 is a prime.

It is a super-2 number, since 2×2809000821² = 15780971224757348082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2809000801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 301605 + ... + 310778.

It is an arithmetic number, because the mean of its divisors is an integer number (257201280).

Almost surely, 2^2809000821 is an apocalyptic number.

It is an amenable number.

2809000821 is a deficient number, since it is larger than the sum of its proper divisors (1306219659).

2809000821 is a wasteful number, since it uses less digits than its factorization.

2809000821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612536.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 2809000821 is about 53000.0077452825. The cubic root of 2809000821 is about 1410.9684041999.

The spelling of 2809000821 in words is "two billion, eight hundred nine million, eight hundred twenty-one", and thus it is an aban number.