128677728 has 144 divisors (see below), whose sum is σ = 368686080. Its totient is φ = 39267072.

The previous prime is 128677697. The next prime is 128677729. The reversal of 128677728 is 827776821.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128677729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1628793 + ... + 1628871.

It is an arithmetic number, because the mean of its divisors is an integer number (2560320).

Almost surely, 2^128677728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128677728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184343040).

128677728 is an abundant number, since it is smaller than the sum of its proper divisors (240008352).

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

128677728 is a wasteful number, since it uses less digits than its factorization.

128677728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 150 counting only the distinct ones).

The product of its digits is 526848, while the sum is 48.

The square root of 128677728 is about 11343.6205860387. The cubic root of 128677728 is about 504.8563169965.

The spelling of 128677728 in words is "one hundred twenty-eight million, six hundred seventy-seven thousand, seven hundred twenty-eight".