389636875681 has 3 divisors (see below), whose sum is σ = 389637499891. Its totient is φ = 389636251472.

The previous prime is 389636875673. The next prime is 389636875703. The reversal of 389636875681 is 186578636983.

The square root of 389636875681 is 624209.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 909565281 + 388727310400 = 30159^2 + 623480^2 .

It is not a de Polignac number, because 389636875681 - 2³ = 389636875673 is a prime.

It is a super-2 number, since 2×389636875681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 389636875681.

It is not an unprimeable number, because it can be changed into a prime (389636875651) 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 2 ways as a sum of consecutive naturals, for example, 312105 + ... + 936313.

Almost surely, 2^389636875681 is an apocalyptic number.

389636875681 is the 624209-th square number.

389636875681 is the 312105-th centered octagonal number.

It is an amenable number.

389636875681 is a deficient number, since it is larger than the sum of its proper divisors (624210).

389636875681 is an frugal number, since it uses more digits than its factorization.

389636875681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248418 (or 624209 counting only the distinct ones).

The product of its digits is 313528320, while the sum is 70.

It can be divided in two parts, 3896368 and 75681, that added together give a square (3972049 = 1993²).

The spelling of 389636875681 in words is "three hundred eighty-nine billion, six hundred thirty-six million, eight hundred seventy-five thousand, six hundred eighty-one".