866896809 has 4 divisors (see below), whose sum is σ = 1155862416. Its totient is φ = 577931204.

The previous prime is 866896753. The next prime is 866896817. The reversal of 866896809 is 908698668.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866896809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (866896829) 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, 144482799 + ... + 144482804.

It is an arithmetic number, because the mean of its divisors is an integer number (288965604).

Almost surely, 2^866896809 is an apocalyptic number.

It is an amenable number.

866896809 is a deficient number, since it is larger than the sum of its proper divisors (288965607).

866896809 is a wasteful number, since it uses less digits than its factorization.

866896809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288965606.

The product of its (nonzero) digits is 8957952, while the sum is 60.

The square root of 866896809 is about 29443.1114014807. Note that the first 3 decimals coincide. The cubic root of 866896809 is about 953.5038876749.

The spelling of 866896809 in words is "eight hundred sixty-six million, eight hundred ninety-six thousand, eight hundred nine".