128381 has 6 divisors (see below), whose sum is σ = 141246. Its totient is φ = 116600.

The previous prime is 128377. The next prime is 128389. The reversal of 128381 is 183821.

128381 is nontrivially palindromic in base 4.

It can be written as a sum of positive squares in only one way, i.e., 116281 + 12100 = 341^2 + 110^2 .

It is not a de Polignac number, because 128381 - 2² = 128377 is a prime.

It is a super-2 number, since 2×128381² = 32963362322, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 128381.

It is not an unprimeable number, because it can be changed into a prime (128389) 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 5 ways as a sum of consecutive naturals, for example, 410 + ... + 651.

It is an arithmetic number, because the mean of its divisors is an integer number (23541).

2¹²⁸³⁸¹ is an apocalyptic number.

128381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128381 is a deficient number, since it is larger than the sum of its proper divisors (12865).

128381 is a wasteful number, since it uses less digits than its factorization.

128381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083 (or 1072 counting only the distinct ones).

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

The square root of 128381 is about 358.3029444479. The cubic root of 128381 is about 50.4467955819.

It can be divided in two parts, 1 and 28381, that added together give a palindrome (28382).

The spelling of 128381 in words is "one hundred twenty-eight thousand, three hundred eighty-one".