188355989 has 2 divisors, whose sum is σ = 188355990. Its totient is φ = 188355988.

The previous prime is 188355977. The next prime is 188356019. The reversal of 188355989 is 989553881.

188355989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159012100 + 29343889 = 12610^2 + 5417^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188355989 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188355289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94177994 + 94177995.

It is an arithmetic number, because the mean of its divisors is an integer number (94177995).

Almost surely, 2^188355989 is an apocalyptic number.

It is an amenable number.

188355989 is a deficient number, since it is larger than the sum of its proper divisors (1).

188355989 is an equidigital number, since it uses as much as digits as its factorization.

188355989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3110400, while the sum is 56.

The square root of 188355989 is about 13724.2846443813. The cubic root of 188355989 is about 573.2267883486.

The spelling of 188355989 in words is "one hundred eighty-eight million, three hundred fifty-five thousand, nine hundred eighty-nine".