381128 has 32 divisors (see below), whose sum is σ = 803520. Its totient is φ = 168000.

The previous prime is 381103. The next prime is 381167. The reversal of 381128 is 821183.

381128 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (23) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5333 + ... + 5403.

It is an arithmetic number, because the mean of its divisors is an integer number (25110).

2³⁸¹¹²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 381128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (401760).

381128 is an abundant number, since it is smaller than the sum of its proper divisors (422392).

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

381128 is a wasteful number, since it uses less digits than its factorization.

381128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 145 counting only the distinct ones).

The product of its digits is 384, while the sum is 23.

The square root of 381128 is about 617.3556511445. The cubic root of 381128 is about 72.5031627633.

The spelling of 381128 in words is "three hundred eighty-one thousand, one hundred twenty-eight".