188731889 has 2 divisors, whose sum is σ = 188731890. Its totient is φ = 188731888.

The previous prime is 188731861. The next prime is 188731891. The reversal of 188731889 is 988137881.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137007025 + 51724864 = 11705^2 + 7192^2 .

It is an emirp because it is prime and its reverse (988137881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 188731889 - 2⁸ = 188731633 is a prime.

Together with 188731891, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 188731889.

It is not a weakly prime, because it can be changed into another prime (188731819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94365944 + 94365945.

It is an arithmetic number, because the mean of its divisors is an integer number (94365945).

Almost surely, 2^188731889 is an apocalyptic number.

It is an amenable number.

188731889 is a deficient number, since it is larger than the sum of its proper divisors (1).

188731889 is an equidigital number, since it uses as much as digits as its factorization.

188731889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 774144, while the sum is 53.

The square root of 188731889 is about 13737.9725214458. The cubic root of 188731889 is about 573.6078624494.

The spelling of 188731889 in words is "one hundred eighty-eight million, seven hundred thirty-one thousand, eight hundred eighty-nine".