128557206 has 48 divisors (see below), whose sum is σ = 292428864. Its totient is φ = 42322824.

The previous prime is 128557193. The next prime is 128557223. The reversal of 128557206 is 602755821.

It is a happy number.

128557206 is a `hidden beast` number, since 1 + 2 + 85 + 572 + 0 + 6 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38745 + ... + 41931.

It is an arithmetic number, because the mean of its divisors is an integer number (6092268).

Almost surely, 2^128557206 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128557206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146214432).

128557206 is an abundant number, since it is smaller than the sum of its proper divisors (163871658).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128557206 is an equidigital number, since it uses as much as digits as its factorization.

128557206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3287 (or 3275 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 128557206 is about 11338.3070164818. The cubic root of 128557206 is about 504.6986484280.

The spelling of 128557206 in words is "one hundred twenty-eight million, five hundred fifty-seven thousand, two hundred six".