189805 has 32 divisors (see below), whose sum is σ = 311040. Its totient is φ = 107520.

The previous prime is 189799. The next prime is 189817. The reversal of 189805 is 508981.

It is not a de Polignac number, because 189805 - 2³ = 189797 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6531 + ... + 6559.

It is an arithmetic number, because the mean of its divisors is an integer number (9720).

2¹⁸⁹⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

189805 is a deficient number, since it is larger than the sum of its proper divisors (121235).

189805 is a wasteful number, since it uses less digits than its factorization.

189805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 189805 is about 435.6661565924. Note that the first 3 decimals coincide. The cubic root of 189805 is about 57.4692967778.

The spelling of 189805 in words is "one hundred eighty-nine thousand, eight hundred five".