2798809 has 6 divisors (see below), whose sum is σ = 3030846. Its totient is φ = 2583360.

The previous prime is 2798777. The next prime is 2798821. The reversal of 2798809 is 9088972.

It can be written as a sum of positive squares in 3 ways, for example, as 222784 + 2576025 = 472^2 + 1605^2 .

It is not a de Polignac number, because 2798809 - 2⁵ = 2798777 is a prime.

It is an Ulam number.

2798809 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2798849) 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, 8112 + ... + 8449.

It is an arithmetic number, because the mean of its divisors is an integer number (505141).

2^2798809 is an apocalyptic number.

It is an amenable number.

2798809 is a deficient number, since it is larger than the sum of its proper divisors (232037).

2798809 is a wasteful number, since it uses less digits than its factorization.

2798809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16587 (or 16574 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 43.

The square root of 2798809 is about 1672.9641358977. The cubic root of 2798809 is about 140.9259876815.

The spelling of 2798809 in words is "two million, seven hundred ninety-eight thousand, eight hundred nine".