389285721 has 12 divisors (see below), whose sum is σ = 613420080. Its totient is φ = 235930680.

The previous prime is 389285707. The next prime is 389285723. The reversal of 389285721 is 127582983.

It is a happy number.

It is not a de Polignac number, because 389285721 - 2¹⁰ = 389284697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (389285723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1965991 + ... + 1966188.

It is an arithmetic number, because the mean of its divisors is an integer number (51118340).

Almost surely, 2^389285721 is an apocalyptic number.

It is an amenable number.

389285721 is a deficient number, since it is larger than the sum of its proper divisors (224134359).

389285721 is a wasteful number, since it uses less digits than its factorization.

389285721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3932196 (or 3932193 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 389285721 is about 19730.3249086273. The cubic root of 389285721 is about 730.1680485075.

The spelling of 389285721 in words is "three hundred eighty-nine million, two hundred eighty-five thousand, seven hundred twenty-one".