189865 has 16 divisors (see below), whose sum is σ = 258048. Its totient is φ = 133056.

The previous prime is 189859. The next prime is 189877. The reversal of 189865 is 568981.

It is a cyclic number.

It is not a de Polignac number, because 189865 - 2⁹ = 189353 is a prime.

It is a Duffinian number.

189865 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1432 + ... + 1558.

It is an arithmetic number, because the mean of its divisors is an integer number (16128).

2¹⁸⁹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

189865 is a deficient number, since it is larger than the sum of its proper divisors (68183).

189865 is a wasteful number, since it uses less digits than its factorization.

189865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168.

The product of its digits is 17280, while the sum is 37.

The square root of 189865 is about 435.7350112167. The cubic root of 189865 is about 57.4753517545.

The spelling of 189865 in words is "one hundred eighty-nine thousand, eight hundred sixty-five".