389924064721 has 9 divisors (see below), whose sum is σ = 390950211483. Its totient is φ = 388900609200.

The previous prime is 389924064709. The next prime is 389924064749. The reversal of 389924064721 is 127460429983.

The square root of 389924064721 is 624439.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 327743655121 + 62180409600 = 572489^2 + 249360^2 .

It is not a de Polignac number, because 389924064721 - 2²³ = 389915676113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (389924064701) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 375287320 + ... + 375288358.

It is an arithmetic number, because the mean of its divisors is an integer number (43438912387).

Almost surely, 2^389924064721 is an apocalyptic number.

389924064721 is the 624439-th square number.

389924064721 is the 312220-th centered octagonal number.

It is an amenable number.

389924064721 is a deficient number, since it is larger than the sum of its proper divisors (1026146762).

389924064721 is an frugal number, since it uses more digits than its factorization.

389924064721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3280 (or 1640 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 55.

The spelling of 389924064721 in words is "three hundred eighty-nine billion, nine hundred twenty-four million, sixty-four thousand, seven hundred twenty-one".