189891 has 16 divisors (see below), whose sum is σ = 303520. Its totient is φ = 116640.

The previous prime is 189887. The next prime is 189901. The reversal of 189891 is 198981.

It is not a de Polignac number, because 189891 - 2² = 189887 is a prime.

It is a Duffinian number.

189891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (189851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81 + ... + 621.

It is an arithmetic number, because the mean of its divisors is an integer number (18970).

2¹⁸⁹⁸⁹¹ is an apocalyptic number.

189891 is a deficient number, since it is larger than the sum of its proper divisors (113629).

189891 is a wasteful number, since it uses less digits than its factorization.

189891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 557 counting only the distinct ones).

The product of its digits is 5184, while the sum is 36.

The square root of 189891 is about 435.7648448418. The cubic root of 189891 is about 57.4779751816.

The spelling of 189891 in words is "one hundred eighty-nine thousand, eight hundred ninety-one".