20189 has 4 divisors (see below), whose sum is σ = 21756. Its totient is φ = 18624.

The previous prime is 20183. The next prime is 20201. The reversal of 20189 is 98102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2500 + 17689 = 50^2 + 133^2 .

It is a cyclic number.

It is not a de Polignac number, because 20189 - 2⁴ = 20173 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20183) 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, 764 + ... + 789.

It is an arithmetic number, because the mean of its divisors is an integer number (5439).

2²⁰¹⁸⁹ is an apocalyptic number.

It is an amenable number.

20189 is a deficient number, since it is larger than the sum of its proper divisors (1567).

20189 is a wasteful number, since it uses less digits than its factorization.

20189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 20189 is about 142.0880009009. The cubic root of 20189 is about 27.2294123880.

The spelling of 20189 in words is "twenty thousand, one hundred eighty-nine".