128557 has 16 divisors (see below), whose sum is σ = 161280. Its totient is φ = 100800.

The previous prime is 128551. The next prime is 128563. The reversal of 128557 is 755821.

It is an interprime number because it is at equal distance from previous prime (128551) and next prime (128563).

It is a cyclic number.

It is not a de Polignac number, because 128557 - 2³ = 128549 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128551) 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 in 15 ways as a sum of consecutive naturals, for example, 4132 + ... + 4162.

It is an arithmetic number, because the mean of its divisors is an integer number (10080).

2¹²⁸⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

128557 is a deficient number, since it is larger than the sum of its proper divisors (32723).

128557 is a wasteful number, since it uses less digits than its factorization.

128557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84.

The product of its digits is 2800, while the sum is 28.

The square root of 128557 is about 358.5484625542. The cubic root of 128557 is about 50.4698378852.

Subtracting 128557 from its reverse (755821), we obtain a square (627264 = 792²).

The spelling of 128557 in words is "one hundred twenty-eight thousand, five hundred fifty-seven".