189131289 has 4 divisors (see below), whose sum is σ = 252175056. Its totient is φ = 126087524.

The previous prime is 189131281. The next prime is 189131311. The reversal of 189131289 is 982131981.

189131289 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 189131289 - 2³ = 189131281 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 189131289.

It is not an unprimeable number, because it can be changed into a prime (189131281) 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, 31521879 + ... + 31521884.

It is an arithmetic number, because the mean of its divisors is an integer number (63043764).

Almost surely, 2^189131289 is an apocalyptic number.

It is an amenable number.

189131289 is a deficient number, since it is larger than the sum of its proper divisors (63043767).

189131289 is an equidigital number, since it uses as much as digits as its factorization.

189131289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63043766.

The product of its digits is 31104, while the sum is 42.

The square root of 189131289 is about 13752.5011906925. The cubic root of 189131289 is about 574.0122059912.

It can be divided in two parts, 189131 and 289, that added together give a triangular number (189420 = T₆₁₅).

The spelling of 189131289 in words is "one hundred eighty-nine million, one hundred thirty-one thousand, two hundred eighty-nine".