128125557 has 40 divisors (see below), whose sum is σ = 221284800. Its totient is φ = 72363456.

The previous prime is 128125537. The next prime is 128125579. The reversal of 128125557 is 755521821.

128125557 is a `hidden beast` number, since 1 + 2 + 81 + 25 + 557 = 666.

It is not a de Polignac number, because 128125557 - 2¹⁰ = 128124533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128125537) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 49194 + ... + 51732.

It is an arithmetic number, because the mean of its divisors is an integer number (5532120).

Almost surely, 2^128125557 is an apocalyptic number.

It is an amenable number.

128125557 is a deficient number, since it is larger than the sum of its proper divisors (93159243).

128125557 is an equidigital number, since it uses as much as digits as its factorization.

128125557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2647 (or 2638 counting only the distinct ones).

The product of its digits is 28000, while the sum is 36.

The square root of 128125557 is about 11319.2560267890. The cubic root of 128125557 is about 504.1331493446.

The spelling of 128125557 in words is "one hundred twenty-eight million, one hundred twenty-five thousand, five hundred fifty-seven".