389922721 has 8 divisors (see below), whose sum is σ = 394202664. Its totient is φ = 385651200.

The previous prime is 389922697. The next prime is 389922737. The reversal of 389922721 is 127229983.

It can be written as a sum of positive squares in 4 ways, for example, as 302238225 + 87684496 = 17385^2 + 9364^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 389922721 - 2¹¹ = 389920673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (389922791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145425 + ... + 148081.

It is an arithmetic number, because the mean of its divisors is an integer number (49275333).

Almost surely, 2^389922721 is an apocalyptic number.

It is an amenable number.

389922721 is a deficient number, since it is larger than the sum of its proper divisors (4279943).

389922721 is a wasteful number, since it uses less digits than its factorization.

389922721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4211.

The product of its digits is 108864, while the sum is 43.

The square root of 389922721 is about 19746.4609740581. The cubic root of 389922721 is about 730.5660968280.

The spelling of 389922721 in words is "three hundred eighty-nine million, nine hundred twenty-two thousand, seven hundred twenty-one".