388681 has 4 divisors (see below), whose sum is σ = 390852. Its totient is φ = 386512.

The previous prime is 388673. The next prime is 388691. The reversal of 388681 is 186883.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 259081 + 129600 = 509^2 + 360^2 .

It is a cyclic number.

It is not a de Polignac number, because 388681 - 2³ = 388673 is a prime.

It is a super-2 number, since 2×388681² = 302145839522, which contains 22 as substring.

It is a Duffinian number.

388681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (388621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 790 + ... + 1183.

It is an arithmetic number, because the mean of its divisors is an integer number (97713).

2³⁸⁸⁶⁸¹ is an apocalyptic number.

It is an amenable number.

388681 is a deficient number, since it is larger than the sum of its proper divisors (2171).

388681 is a wasteful number, since it uses less digits than its factorization.

388681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2170.

The product of its digits is 9216, while the sum is 34.

The square root of 388681 is about 623.4428602526. The cubic root of 388681 is about 72.9789768698.

The spelling of 388681 in words is "three hundred eighty-eight thousand, six hundred eighty-one".