809391869 has 18 divisors (see below), whose sum is σ = 963386298. Its totient is φ = 679192800.

The previous prime is 809391853. The next prime is 809391871. The reversal of 809391869 is 968193908.

It can be written as a sum of positive squares in 3 ways, for example, as 7086244 + 802305625 = 2662^2 + 28325^2 .

It is not a de Polignac number, because 809391869 - 2⁴ = 809391853 is a prime.

It is a super-2 number, since 2×809391869² = 1310230395206626322, 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 809391869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809391809) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 659 + ... + 40239.

It is an arithmetic number, because the mean of its divisors is an integer number (53521461).

Almost surely, 2^809391869 is an apocalyptic number.

It is an amenable number.

809391869 is a deficient number, since it is larger than the sum of its proper divisors (153994429).

809391869 is a wasteful number, since it uses less digits than its factorization.

809391869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39629 (or 39605 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 53.

The square root of 809391869 is about 28449.8131628311. The cubic root of 809391869 is about 931.9364088849.

The spelling of 809391869 in words is "eight hundred nine million, three hundred ninety-one thousand, eight hundred sixty-nine".