381728 has 24 divisors (see below), whose sum is σ = 766080. Its totient is φ = 187200.

The previous prime is 381713. The next prime is 381737. The reversal of 381728 is 827183.

381728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 381728.

It is an unprimeable number.

381728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2453 + ... + 2603.

It is an arithmetic number, because the mean of its divisors is an integer number (31920).

2³⁸¹⁷²⁸ is an apocalyptic number.

It is an amenable number.

381728 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

381728 is a wasteful number, since it uses less digits than its factorization.

With its successor (381729) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (240).

381728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240 (or 232 counting only the distinct ones).

The product of its digits is 2688, while the sum is 29.

The square root of 381728 is about 617.8414035980. The cubic root of 381728 is about 72.5411894365.

The spelling of 381728 in words is "three hundred eighty-one thousand, seven hundred twenty-eight".