65633128728 has 96 divisors (see below), whose sum is σ = 169321878960. Its totient is φ = 21185176320.

The previous prime is 65633128727. The next prime is 65633128747. The reversal of 65633128728 is 82782133656.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65633128727) 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, 155897958 + ... + 155898378.

Almost surely, 2^65633128728 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 65633128728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84660939480).

65633128728 is an abundant number, since it is smaller than the sum of its proper divisors (103688750232).

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

65633128728 is a wasteful number, since it uses less digits than its factorization.

65633128728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305 (or 882 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 51.

The spelling of 65633128728 in words is "sixty-five billion, six hundred thirty-three million, one hundred twenty-eight thousand, seven hundred twenty-eight".