128656 has 40 divisors (see below), whose sum is σ = 294624. Its totient is φ = 53760.

The previous prime is 128629. The next prime is 128657. The reversal of 128656 is 656821.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (128657) by changing a digit.

128656 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2971 + ... + 3013.

2¹²⁸⁶⁵⁶ is an apocalyptic number.

128656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147312).

128656 is an abundant number, since it is smaller than the sum of its proper divisors (165968).

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

128656 is a wasteful number, since it uses less digits than its factorization.

128656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79 (or 73 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 128656 is about 358.6864926367. The cubic root of 128656 is about 50.4827899399.

It can be divided in two parts, 128 and 656, that added together give a square (784 = 28²).

The spelling of 128656 in words is "one hundred twenty-eight thousand, six hundred fifty-six".