389135809 has 2 divisors, whose sum is σ = 389135810. Its totient is φ = 389135808.

The previous prime is 389135783. The next prime is 389135821. The reversal of 389135809 is 908531983.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 381030400 + 8105409 = 19520^2 + 2847^2 .

It is a cyclic number.

It is not a de Polignac number, because 389135809 - 2⁹ = 389135297 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (389135849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194567904 + 194567905.

It is an arithmetic number, because the mean of its divisors is an integer number (194567905).

Almost surely, 2^389135809 is an apocalyptic number.

It is an amenable number.

389135809 is a deficient number, since it is larger than the sum of its proper divisors (1).

389135809 is an equidigital number, since it uses as much as digits as its factorization.

389135809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 46.

The square root of 389135809 is about 19726.5255176881. The cubic root of 389135809 is about 730.0743084425.

The spelling of 389135809 in words is "three hundred eighty-nine million, one hundred thirty-five thousand, eight hundred nine".