189381 has 4 divisors (see below), whose sum is σ = 252512. Its totient is φ = 126252.

The previous prime is 189377. The next prime is 189389. The reversal of 189381 is 183981.

189381 is nontrivially palindromic in base 12.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 189381 - 2² = 189377 is a prime.

It is a super-2 number, since 2×189381² = 71730326322, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189389) 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, 31561 + ... + 31566.

It is an arithmetic number, because the mean of its divisors is an integer number (63128).

2¹⁸⁹³⁸¹ is an apocalyptic number.

It is an amenable number.

189381 is a deficient number, since it is larger than the sum of its proper divisors (63131).

189381 is an equidigital number, since it uses as much as digits as its factorization.

189381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63130.

The product of its digits is 1728, while the sum is 30.

The square root of 189381 is about 435.1792734035. The cubic root of 189381 is about 57.4264718635.

The spelling of 189381 in words is "one hundred eighty-nine thousand, three hundred eighty-one".