389331521 has 4 divisors (see below), whose sum is σ = 389421444. Its totient is φ = 389241600.

The previous prime is 389331469. The next prime is 389331539. The reversal of 389331521 is 125133983.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125133983 = 13 ⋅9625691.

It can be written as a sum of positive squares in 2 ways, for example, as 206784400 + 182547121 = 14380^2 + 13511^2 .

It is a cyclic number.

It is not a de Polignac number, because 389331521 - 2⁶ = 389331457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (389331421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38120 + ... + 47241.

It is an arithmetic number, because the mean of its divisors is an integer number (97355361).

Almost surely, 2^389331521 is an apocalyptic number.

It is an amenable number.

389331521 is a deficient number, since it is larger than the sum of its proper divisors (89923).

389331521 is an equidigital number, since it uses as much as digits as its factorization.

389331521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89922.

The product of its digits is 19440, while the sum is 35.

The square root of 389331521 is about 19731.4855244100. The cubic root of 389331521 is about 730.1966824760.

The spelling of 389331521 in words is "three hundred eighty-nine million, three hundred thirty-one thousand, five hundred twenty-one".