188730989 has 2 divisors, whose sum is σ = 188730990. Its totient is φ = 188730988.

The previous prime is 188730973. The next prime is 188731001. The reversal of 188730989 is 989037881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188512900 + 218089 = 13730^2 + 467^2 .

It is a cyclic number.

It is not a de Polignac number, because 188730989 - 2⁴ = 188730973 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 188730989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188730389) 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 as a sum of consecutive naturals, namely, 94365494 + 94365495.

It is an arithmetic number, because the mean of its divisors is an integer number (94365495).

Almost surely, 2^188730989 is an apocalyptic number.

It is an amenable number.

188730989 is a deficient number, since it is larger than the sum of its proper divisors (1).

188730989 is an equidigital number, since it uses as much as digits as its factorization.

188730989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 870912, while the sum is 53.

The square root of 188730989 is about 13737.9397654816. The cubic root of 188730989 is about 573.6069506659.

The spelling of 188730989 in words is "one hundred eighty-eight million, seven hundred thirty thousand, nine hundred eighty-nine".