189581 has 12 divisors (see below), whose sum is σ = 227772. Its totient is φ = 157248.

The previous prime is 189559. The next prime is 189583. The reversal of 189581 is 185981.

It is a happy number.

189581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 122500 + 67081 = 350^2 + 259^2 .

It is not a de Polignac number, because 189581 - 2⁶ = 189517 is a prime.

It is a super-2 number, since 2×189581² = 71881911122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189583) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2561 + ... + 2633.

It is an arithmetic number, because the mean of its divisors is an integer number (18981).

2¹⁸⁹⁵⁸¹ is an apocalyptic number.

It is an amenable number.

189581 is a deficient number, since it is larger than the sum of its proper divisors (38191).

189581 is an equidigital number, since it uses as much as digits as its factorization.

189581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 133 counting only the distinct ones).

The product of its digits is 2880, while the sum is 32.

The square root of 189581 is about 435.4090031224. The cubic root of 189581 is about 57.4466802505.

Subtracting from 189581 its reverse (185981), we obtain a square (3600 = 60²).

The spelling of 189581 in words is "one hundred eighty-nine thousand, five hundred eighty-one".