128657 has 2 divisors, whose sum is σ = 128658. Its totient is φ = 128656.

The previous prime is 128629. The next prime is 128659. The reversal of 128657 is 756821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 101761 + 26896 = 319^2 + 164^2 .

It is a cyclic number.

It is not a de Polignac number, because 128657 - 2¹² = 124561 is a prime.

Together with 128659, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 11.

It is not a weakly prime, because it can be changed into another prime (128659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64328 + 64329.

It is an arithmetic number, because the mean of its divisors is an integer number (64329).

2¹²⁸⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

128657 is a deficient number, since it is larger than the sum of its proper divisors (1).

128657 is an equidigital number, since it uses as much as digits as its factorization.

128657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 29.

The square root of 128657 is about 358.6878866090. The cubic root of 128657 is about 50.4829207349.

The spelling of 128657 in words is "one hundred twenty-eight thousand, six hundred fifty-seven".