864552809 has 2 divisors, whose sum is σ = 864552810. Its totient is φ = 864552808.

The previous prime is 864552803. The next prime is 864552811. The reversal of 864552809 is 908255468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 686597209 + 177955600 = 26203^2 + 13340^2 .

It is a cyclic number.

It is not a de Polignac number, because 864552809 - 2²⁰ = 863504233 is a prime.

It is a super-3 number, since 3×864552809³ (a number of 28 digits) contains 333 as substring.

Together with 864552811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (864552803) 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 as a sum of consecutive naturals, namely, 432276404 + 432276405.

It is an arithmetic number, because the mean of its divisors is an integer number (432276405).

Almost surely, 2^864552809 is an apocalyptic number.

It is an amenable number.

864552809 is a deficient number, since it is larger than the sum of its proper divisors (1).

864552809 is an equidigital number, since it uses as much as digits as its factorization.

864552809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 691200, while the sum is 47.

The square root of 864552809 is about 29403.2788817846. The cubic root of 864552809 is about 952.6437197225.

The spelling of 864552809 in words is "eight hundred sixty-four million, five hundred fifty-two thousand, eight hundred nine".