864758809 has 2 divisors, whose sum is σ = 864758810. Its totient is φ = 864758808.

The previous prime is 864758789. The next prime is 864758819. The reversal of 864758809 is 908857468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 753667209 + 111091600 = 27453^2 + 10540^2 .

It is a cyclic number.

It is not a de Polignac number, because 864758809 - 2²⁹ = 327887897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 864758809.

It is not a weakly prime, because it can be changed into another prime (864758819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432379404 + 432379405.

It is an arithmetic number, because the mean of its divisors is an integer number (432379405).

Almost surely, 2^864758809 is an apocalyptic number.

It is an amenable number.

864758809 is a deficient number, since it is larger than the sum of its proper divisors (1).

864758809 is an equidigital number, since it uses as much as digits as its factorization.

864758809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3870720, while the sum is 55.

The square root of 864758809 is about 29406.7816838225. The cubic root of 864758809 is about 952.7193769561.

The spelling of 864758809 in words is "eight hundred sixty-four million, seven hundred fifty-eight thousand, eight hundred nine".