864189817 has 2 divisors, whose sum is σ = 864189818. Its totient is φ = 864189816.

The previous prime is 864189793. The next prime is 864189853. The reversal of 864189817 is 718981468.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 482417296 + 381772521 = 21964^2 + 19539^2 .

It is a cyclic number.

It is not a de Polignac number, because 864189817 - 2²³ = 855801209 is a prime.

It is not a weakly prime, because it can be changed into another prime (864189617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432094908 + 432094909.

It is an arithmetic number, because the mean of its divisors is an integer number (432094909).

Almost surely, 2^864189817 is an apocalyptic number.

It is an amenable number.

864189817 is a deficient number, since it is larger than the sum of its proper divisors (1).

864189817 is an equidigital number, since it uses as much as digits as its factorization.

864189817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 774144, while the sum is 52.

The square root of 864189817 is about 29397.1055888161. The cubic root of 864189817 is about 952.5103750796.

The spelling of 864189817 in words is "eight hundred sixty-four million, one hundred eighty-nine thousand, eight hundred seventeen".