189431139 has 4 divisors (see below), whose sum is σ = 252574856. Its totient is φ = 126287424.

The previous prime is 189431113. The next prime is 189431147. The reversal of 189431139 is 931134981.

It is a happy number.

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

It is not a de Polignac number, because 189431139 - 2⁸ = 189430883 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 189431097 and 189431106.

It is not an unprimeable number, because it can be changed into a prime (189431339) 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, 31571854 + ... + 31571859.

It is an arithmetic number, because the mean of its divisors is an integer number (63143714).

Almost surely, 2^189431139 is an apocalyptic number.

189431139 is a deficient number, since it is larger than the sum of its proper divisors (63143717).

189431139 is an equidigital number, since it uses as much as digits as its factorization.

189431139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63143716.

The product of its digits is 23328, while the sum is 39.

The square root of 189431139 is about 13763.3985265268. The cubic root of 189431139 is about 574.3153934086.

It can be divided in two parts, 1894 and 31139, that added together give a palindrome (33033).

The spelling of 189431139 in words is "one hundred eighty-nine million, four hundred thirty-one thousand, one hundred thirty-nine".