128656530 has 48 divisors (see below), whose sum is σ = 336757824. Its totient is φ = 34077600.

The previous prime is 128656523. The next prime is 128656537. The reversal of 128656530 is 35656821.

128656530 is a `hidden beast` number, since 12 + 86 + 565 + 3 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (128656523) and next prime (128656537).

It is not an unprimeable number, because it can be changed into a prime (128656537) by changing a digit.

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, 8857 + ... + 18323.

It is an arithmetic number, because the mean of its divisors is an integer number (7015788).

Almost surely, 2^128656530 is an apocalyptic number.

128656530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 128656530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168378912).

128656530 is an abundant number, since it is smaller than the sum of its proper divisors (208101294).

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

128656530 is a wasteful number, since it uses less digits than its factorization.

128656530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9631 (or 9628 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 128656530 is about 11342.6861897877. The cubic root of 128656530 is about 504.8285926133.

The spelling of 128656530 in words is "one hundred twenty-eight million, six hundred fifty-six thousand, five hundred thirty".