189618728 has 16 divisors (see below), whose sum is σ = 382884180. Its totient is φ = 87516288.

The previous prime is 189618721. The next prime is 189618749. The reversal of 189618728 is 827816981.

It can be written as a sum of positive squares in 2 ways, for example, as 188183524 + 1435204 = 13718^2 + 1198^2 .

It is not an unprimeable number, because it can be changed into a prime (189618721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 911525 + ... + 911732.

Almost surely, 2^189618728 is an apocalyptic number.

It is an amenable number.

189618728 is an abundant number, since it is smaller than the sum of its proper divisors (193265452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

189618728 is a wasteful number, since it uses less digits than its factorization.

189618728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823276 (or 1823272 counting only the distinct ones).

The product of its digits is 387072, while the sum is 50.

The square root of 189618728 is about 13770.2116178365. The cubic root of 189618728 is about 574.5049076704.

The spelling of 189618728 in words is "one hundred eighty-nine million, six hundred eighteen thousand, seven hundred twenty-eight".