809904389 has 6 divisors (see below), whose sum is σ = 942133734. Its totient is φ = 694203720.

The previous prime is 809904379. The next prime is 809904397. The reversal of 809904389 is 983409908.

It can be written as a sum of positive squares in only one way, i.e., 571449025 + 238455364 = 23905^2 + 15442^2 .

It is not a de Polignac number, because 809904389 - 2¹⁶ = 809838853 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 (809904379) 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, 8264282 + ... + 8264379.

It is an arithmetic number, because the mean of its divisors is an integer number (157022289).

Almost surely, 2^809904389 is an apocalyptic number.

It is an amenable number.

809904389 is a deficient number, since it is larger than the sum of its proper divisors (132229345).

809904389 is a wasteful number, since it uses less digits than its factorization.

809904389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16528675 (or 16528668 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 50.

The square root of 809904389 is about 28458.8191778928. The cubic root of 809904389 is about 932.1330731075.

The spelling of 809904389 in words is "eight hundred nine million, nine hundred four thousand, three hundred eighty-nine".