809738689 has 4 divisors (see below), whose sum is σ = 812749140. Its totient is φ = 806728240.

The previous prime is 809738687. The next prime is 809738749. The reversal of 809738689 is 986837908.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 214769025 + 594969664 = 14655^2 + 24392^2 .

It is a cyclic number.

It is not a de Polignac number, because 809738689 - 2¹ = 809738687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809738681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1504822 + ... + 1505359.

It is an arithmetic number, because the mean of its divisors is an integer number (203187285).

Almost surely, 2^809738689 is an apocalyptic number.

It is an amenable number.

809738689 is a deficient number, since it is larger than the sum of its proper divisors (3010451).

809738689 is a wasteful number, since it uses less digits than its factorization.

809738689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3010450.

The product of its (nonzero) digits is 5225472, while the sum is 58.

The square root of 809738689 is about 28455.9078048830. The cubic root of 809738689 is about 932.0694997661.

The spelling of 809738689 in words is "eight hundred nine million, seven hundred thirty-eight thousand, six hundred eighty-nine".