128401657 has 2 divisors, whose sum is σ = 128401658. Its totient is φ = 128401656.

The previous prime is 128401649. The next prime is 128401661. The reversal of 128401657 is 756104821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87684496 + 40717161 = 9364^2 + 6381^2 .

It is a cyclic number.

It is not a de Polignac number, because 128401657 - 2³ = 128401649 is a prime.

It is not a weakly prime, because it can be changed into another prime (128401607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64200828 + 64200829.

It is an arithmetic number, because the mean of its divisors is an integer number (64200829).

Almost surely, 2^128401657 is an apocalyptic number.

It is an amenable number.

128401657 is a deficient number, since it is larger than the sum of its proper divisors (1).

128401657 is an equidigital number, since it uses as much as digits as its factorization.

128401657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 128401657 is about 11331.4454947284. The cubic root of 128401657 is about 504.4950113168.

The spelling of 128401657 in words is "one hundred twenty-eight million, four hundred one thousand, six hundred fifty-seven".