189999 has 16 divisors (see below), whose sum is σ = 291840. Its totient is φ = 122040.

The previous prime is 189997. The next prime is 190027. The reversal of 189999 is 999981.

189999 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 189999 - 2¹ = 189997 is a prime.

189999 is a modest number, since divided by 999 gives 189 as remainder.

189999 is strictly pandigital in base 7.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189997) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 724 + ... + 950.

It is an arithmetic number, because the mean of its divisors is an integer number (18240).

2¹⁸⁹⁹⁹⁹ is an apocalyptic number.

189999 is a deficient number, since it is larger than the sum of its proper divisors (101841).

189999 is a wasteful number, since it uses less digits than its factorization.

189999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267 (or 261 counting only the distinct ones).

The product of its digits is 52488, while the sum is 45.

The square root of 189999 is about 435.8887472739. Note that the first 3 decimals coincide. The cubic root of 189999 is about 57.4888699314.

It can be divided in two parts, 1 and 89999, that added together give a square (90000 = 300²).

The spelling of 189999 in words is "one hundred eighty-nine thousand, nine hundred ninety-nine".