1230128657 has 2 divisors, whose sum is σ = 1230128658. Its totient is φ = 1230128656.

The previous prime is 1230128611. The next prime is 1230128659. The reversal of 1230128657 is 7568210321.

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., 781705681 + 448422976 = 27959^2 + 21176^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1230128657 is a prime.

Together with 1230128659, 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 (1230128659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615064328 + 615064329.

It is an arithmetic number, because the mean of its divisors is an integer number (615064329).

Almost surely, 2^1230128657 is an apocalyptic number.

It is an amenable number.

1230128657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1230128657 is an equidigital number, since it uses as much as digits as its factorization.

1230128657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 1230128657 is about 35073.1900031919. The cubic root of 1230128657 is about 1071.4786256836.

Adding to 1230128657 its reverse (7568210321), we get a palindrome (8798338978).

The spelling of 1230128657 in words is "one billion, two hundred thirty million, one hundred twenty-eight thousand, six hundred fifty-seven".