811928809 has 8 divisors (see below), whose sum is σ = 816451272. Its totient is φ = 807415680.

The previous prime is 811928801. The next prime is 811928839. The reversal of 811928809 is 908829118.

It can be written as a sum of positive squares in 4 ways, for example, as 220077225 + 591851584 = 14835^2 + 24328^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 811928809 - 2³ = 811928801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811928801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236187 + ... + 239599.

It is an arithmetic number, because the mean of its divisors is an integer number (102056409).

Almost surely, 2^811928809 is an apocalyptic number.

It is an amenable number.

811928809 is a deficient number, since it is larger than the sum of its proper divisors (4522463).

811928809 is a wasteful number, since it uses less digits than its factorization.

811928809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4667.

The product of its (nonzero) digits is 82944, while the sum is 46.

The square root of 811928809 is about 28494.3645130050. The cubic root of 811928809 is about 932.9090736585.

The spelling of 811928809 in words is "eight hundred eleven million, nine hundred twenty-eight thousand, eight hundred nine".