189919999 has 4 divisors (see below), whose sum is σ = 189947664. Its totient is φ = 189892336.

The previous prime is 189919979. The next prime is 189920011. The reversal of 189919999 is 999919981.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 189919999 - 2²³ = 181531391 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 189919999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189919969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5139 + ... + 20155.

It is an arithmetic number, because the mean of its divisors is an integer number (47486916).

Almost surely, 2^189919999 is an apocalyptic number.

189919999 is a deficient number, since it is larger than the sum of its proper divisors (27665).

189919999 is a wasteful number, since it uses less digits than its factorization.

189919999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27664.

The product of its digits is 4251528, while the sum is 64.

The square root of 189919999 is about 13781.1465052803. The cubic root of 189919999 is about 574.8090092838.

The spelling of 189919999 in words is "one hundred eighty-nine million, nine hundred nineteen thousand, nine hundred ninety-nine".