388444681 has 3 divisors (see below), whose sum is σ = 388464391. Its totient is φ = 388424972.

The previous prime is 388444597. The next prime is 388444697. The reversal of 388444681 is 186444883.

The square root of 388444681 is 19709.

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., 198556281 + 189888400 = 14091^2 + 13780^2 .

It is not a de Polignac number, because 388444681 - 2¹⁵ = 388411913 is a prime.

It is a super-2 number, since 2×388444681² = 301778540394383522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (388444481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 9855 + ... + 29563.

Almost surely, 2^388444681 is an apocalyptic number.

388444681 is the 19709-th square number.

388444681 is the 9855-th centered octagonal number.

It is an amenable number.

388444681 is a deficient number, since it is larger than the sum of its proper divisors (19710).

388444681 is an frugal number, since it uses more digits than its factorization.

388444681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39418 (or 19709 counting only the distinct ones).

The product of its digits is 589824, while the sum is 46.

The cubic root of 388444681 is about 729.6418340567.

Multiplying 388444681 by its product of digits (589824), we get a square (229113995526144 = 15136512²).

The spelling of 388444681 in words is "three hundred eighty-eight million, four hundred forty-four thousand, six hundred eighty-one".