188159989 has 2 divisors, whose sum is σ = 188159990. Its totient is φ = 188159988.

The previous prime is 188159981. The next prime is 188159999. The reversal of 188159989 is 989951881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 183385764 + 4774225 = 13542^2 + 2185^2 .

It is an emirp because it is prime and its reverse (989951881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 188159989 - 2³ = 188159981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188159981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94079994 + 94079995.

It is an arithmetic number, because the mean of its divisors is an integer number (94079995).

Almost surely, 2^188159989 is an apocalyptic number.

It is an amenable number.

188159989 is a deficient number, since it is larger than the sum of its proper divisors (1).

188159989 is an equidigital number, since it uses as much as digits as its factorization.

188159989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1866240, while the sum is 58.

The square root of 188159989 is about 13717.1421586276. The cubic root of 188159989 is about 573.0278893660.

The spelling of 188159989 in words is "one hundred eighty-eight million, one hundred fifty-nine thousand, nine hundred eighty-nine".