189128657 has 2 divisors, whose sum is σ = 189128658. Its totient is φ = 189128656.

The previous prime is 189128651. The next prime is 189128659. The reversal of 189128657 is 756821981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144024001 + 45104656 = 12001^2 + 6716^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189128657 is a prime.

Together with 189128659, 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 (189128651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94564328 + 94564329.

It is an arithmetic number, because the mean of its divisors is an integer number (94564329).

Almost surely, 2^189128657 is an apocalyptic number.

It is an amenable number.

189128657 is a deficient number, since it is larger than the sum of its proper divisors (1).

189128657 is an equidigital number, since it uses as much as digits as its factorization.

189128657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 47.

The square root of 189128657 is about 13752.4054986755. The cubic root of 189128657 is about 574.0095432780.

The spelling of 189128657 in words is "one hundred eighty-nine million, one hundred twenty-eight thousand, six hundred fifty-seven".