388402257 has 4 divisors (see below), whose sum is σ = 517869680. Its totient is φ = 258934836.

The previous prime is 388402243. The next prime is 388402291. The reversal of 388402257 is 752204883.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 752204883 = 3 ⋅250734961.

It is not a de Polignac number, because 388402257 - 2⁴ = 388402241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (388402297) 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 3 ways as a sum of consecutive naturals, for example, 64733707 + ... + 64733712.

It is an arithmetic number, because the mean of its divisors is an integer number (129467420).

Almost surely, 2^388402257 is an apocalyptic number.

It is an amenable number.

388402257 is a deficient number, since it is larger than the sum of its proper divisors (129467423).

388402257 is a wasteful number, since it uses less digits than its factorization.

388402257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129467422.

The product of its (nonzero) digits is 107520, while the sum is 39.

The square root of 388402257 is about 19707.9237110356. The cubic root of 388402257 is about 729.6152704698.

The spelling of 388402257 in words is "three hundred eighty-eight million, four hundred two thousand, two hundred fifty-seven".