188381 has 4 divisors (see below), whose sum is σ = 189372. Its totient is φ = 187392.

The previous prime is 188369. The next prime is 188389. The reversal of 188381 is 183881.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 184900 + 3481 = 430^2 + 59^2 .

It is a cyclic number.

It is not a de Polignac number, because 188381 - 2⁶ = 188317 is a prime.

It is a super-2 number, since 2×188381² = 70974802322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (188389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110 + ... + 623.

It is an arithmetic number, because the mean of its divisors is an integer number (47343).

2¹⁸⁸³⁸¹ is an apocalyptic number.

It is an amenable number.

188381 is a deficient number, since it is larger than the sum of its proper divisors (991).

188381 is an equidigital number, since it uses as much as digits as its factorization.

188381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990.

The product of its digits is 1536, while the sum is 29.

The square root of 188381 is about 434.0288008877. The cubic root of 188381 is about 57.3252159351.

The spelling of 188381 in words is "one hundred eighty-eight thousand, three hundred eighty-one".