189591 has 4 divisors (see below), whose sum is σ = 252792. Its totient is φ = 126392.

The previous prime is 189583. The next prime is 189593. The reversal of 189591 is 195981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 195981 = 3 ⋅65327.

It is a cyclic number.

It is not a de Polignac number, because 189591 - 2³ = 189583 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189593) 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, 31596 + ... + 31601.

It is an arithmetic number, because the mean of its divisors is an integer number (63198).

2¹⁸⁹⁵⁹¹ is an apocalyptic number.

189591 is a deficient number, since it is larger than the sum of its proper divisors (63201).

189591 is an equidigital number, since it uses as much as digits as its factorization.

189591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63200.

The product of its digits is 3240, while the sum is 33.

The square root of 189591 is about 435.4204864266. The cubic root of 189591 is about 57.4476902967.

It can be divided in two parts, 189 and 591, that added together give a triangular number (780 = T₃₉).

The spelling of 189591 in words is "one hundred eighty-nine thousand, five hundred ninety-one".