388018113921 has 27 divisors (see below), whose sum is σ = 567081858889. Its totient is φ = 255662607552.

The previous prime is 388018113893. The next prime is 388018113949. The reversal of 388018113921 is 129311810883.

The square root of 388018113921 is 622911.

It is a perfect power (a square), and thus also a powerful number.

388018113921 is a `hidden beast` number, since 3 + 8 + 80 + 181 + 1 + 392 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (388018113893) and next prime (388018113949).

It can be written as a sum of positive squares in 4 ways, for example, as 86656640625 + 301361473296 = 294375^2 + 548964^2 .

It is not a de Polignac number, because 388018113921 - 2²⁷ = 387883896193 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (388018113971) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 166316071 + ... + 166318403.

Almost surely, 2^388018113921 is an apocalyptic number.

388018113921 is the 622911-st square number.

388018113921 is the 311456-th centered octagonal number.

It is an amenable number.

388018113921 is a deficient number, since it is larger than the sum of its proper divisors (179063744968).

388018113921 is an frugal number, since it uses more digits than its factorization.

388018113921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4850 (or 2425 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The spelling of 388018113921 in words is "three hundred eighty-eight billion, eighteen million, one hundred thirteen thousand, nine hundred twenty-one".