388920257 has 12 divisors (see below), whose sum is σ = 429296868. Its totient is φ = 352070400.

The previous prime is 388920223. The next prime is 388920269. The reversal of 388920257 is 752029883.

It can be written as a sum of positive squares in 2 ways, for example, as 201668401 + 187251856 = 14201^2 + 13684^2 .

It is not a de Polignac number, because 388920257 - 2⁸ = 388920001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (388920457) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22493 + ... + 35829.

It is an arithmetic number, because the mean of its divisors is an integer number (35774739).

Almost surely, 2^388920257 is an apocalyptic number.

It is an amenable number.

388920257 is a deficient number, since it is larger than the sum of its proper divisors (40376611).

388920257 is a wasteful number, since it uses less digits than its factorization.

388920257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13600 (or 13589 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 388920257 is about 19721.0612544051. The cubic root of 388920257 is about 729.9394814408.

The spelling of 388920257 in words is "three hundred eighty-eight million, nine hundred twenty thousand, two hundred fifty-seven".