2128636728 has 96 divisors (see below), whose sum is σ = 6127804800. Its totient is φ = 665630784.

The previous prime is 2128636667. The next prime is 2128636739. The reversal of 2128636728 is 8276368212.

2128636728 is a `hidden beast` number, since 2 + 1 + 2 + 8 + 636 + 7 + 2 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 133351 + ... + 148457.

It is an arithmetic number, because the mean of its divisors is an integer number (63831300).

Almost surely, 2^2128636728 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 2128636728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3063902400).

2128636728 is an abundant number, since it is smaller than the sum of its proper divisors (3999168072).

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

2128636728 is a wasteful number, since it uses less digits than its factorization.

2128636728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15241 (or 15234 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 2128636728 is about 46137.1512774684. The cubic root of 2128636728 is about 1286.3737931609.

The spelling of 2128636728 in words is "two billion, one hundred twenty-eight million, six hundred thirty-six thousand, seven hundred twenty-eight".