388740397 has 4 divisors (see below), whose sum is σ = 390888316. Its totient is φ = 386592480.

The previous prime is 388740379. The next prime is 388740413. The reversal of 388740397 is 793047883.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793047883 = 7949 ⋅99767.

It can be written as a sum of positive squares in 2 ways, for example, as 111218116 + 277522281 = 10546^2 + 16659^2 .

It is a cyclic number.

It is not a de Polignac number, because 388740397 - 2²³ = 380351789 is a prime.

It is a super-2 number, since 2×388740397² = 302238192519435218, which 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 388740397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (388740307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1073688 + ... + 1074049.

It is an arithmetic number, because the mean of its divisors is an integer number (97722079).

Almost surely, 2^388740397 is an apocalyptic number.

It is an amenable number.

388740397 is a deficient number, since it is larger than the sum of its proper divisors (2147919).

388740397 is a wasteful number, since it uses less digits than its factorization.

388740397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2147918.

The product of its (nonzero) digits is 1016064, while the sum is 49.

The square root of 388740397 is about 19716.5006276469. The cubic root of 388740397 is about 729.8269415252.

The spelling of 388740397 in words is "three hundred eighty-eight million, seven hundred forty thousand, three hundred ninety-seven".