188899889 has 2 divisors, whose sum is σ = 188899890. Its totient is φ = 188899888.

The previous prime is 188899849. The next prime is 188899891. The reversal of 188899889 is 988998881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94965025 + 93934864 = 9745^2 + 9692^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188899889 is a prime.

Together with 188899891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (188899829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94449944 + 94449945.

It is an arithmetic number, because the mean of its divisors is an integer number (94449945).

Almost surely, 2^188899889 is an apocalyptic number.

It is an amenable number.

188899889 is a deficient number, since it is larger than the sum of its proper divisors (1).

188899889 is an equidigital number, since it uses as much as digits as its factorization.

188899889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23887872, while the sum is 68.

The square root of 188899889 is about 13744.0856007230. The cubic root of 188899889 is about 573.7780112993.

The spelling of 188899889 in words is "one hundred eighty-eight million, eight hundred ninety-nine thousand, eight hundred eighty-nine".