128256726 has 64 divisors (see below), whose sum is σ = 298771200. Its totient is φ = 36360576.

The previous prime is 128256701. The next prime is 128256757. The reversal of 128256726 is 627652821.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53665 + ... + 56003.

It is an arithmetic number, because the mean of its divisors is an integer number (4668300).

Almost surely, 2^128256726 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128256726, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149385600).

128256726 is an abundant number, since it is smaller than the sum of its proper divisors (170514474).

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

128256726 is a wasteful number, since it uses less digits than its factorization.

128256726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2413.

The product of its digits is 80640, while the sum is 39.

The square root of 128256726 is about 11325.0486091672. The cubic root of 128256726 is about 504.3051267124.

The spelling of 128256726 in words is "one hundred twenty-eight million, two hundred fifty-six thousand, seven hundred twenty-six".