189939 has 4 divisors (see below), whose sum is σ = 253256. Its totient is φ = 126624.

The previous prime is 189929. The next prime is 189947. The reversal of 189939 is 939981.

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

It is a de Polignac number, because none of the positive numbers 2^k-189939 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 189897 and 189906.

It is not an unprimeable number, because it can be changed into a prime (189929) 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, 31654 + ... + 31659.

It is an arithmetic number, because the mean of its divisors is an integer number (63314).

2¹⁸⁹⁹³⁹ is an apocalyptic number.

189939 is a deficient number, since it is larger than the sum of its proper divisors (63317).

189939 is an equidigital number, since it uses as much as digits as its factorization.

189939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63316.

The product of its digits is 17496, while the sum is 39.

The square root of 189939 is about 435.8199169382. The cubic root of 189939 is about 57.4828178025.

It can be divided in two parts, 189 and 939, that added together give a triangular number (1128 = T₄₇).

The spelling of 189939 in words is "one hundred eighty-nine thousand, nine hundred thirty-nine".