2809000823 has 4 divisors (see below), whose sum is σ = 2840562720. Its totient is φ = 2777438928.

The previous prime is 2809000819. The next prime is 2809000849. The reversal of 2809000823 is 3280009082.

It is a happy number.

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 2809000823 - 2² = 2809000819 is a prime.

It is a super-2 number, since 2×2809000823² = 15780971247229354658, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2809000823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2809000853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15780815 + ... + 15780992.

It is an arithmetic number, because the mean of its divisors is an integer number (710140680).

Almost surely, 2^2809000823 is an apocalyptic number.

2809000823 is a deficient number, since it is larger than the sum of its proper divisors (31561897).

2809000823 is an equidigital number, since it uses as much as digits as its factorization.

2809000823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31561896.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 2809000823 is about 53000.0077641504. The cubic root of 2809000823 is about 1410.9684045348.

The spelling of 2809000823 in words is "two billion, eight hundred nine million, eight hundred twenty-three", and thus it is an aban number.