66332728 has 64 divisors (see below), whose sum is σ = 156038400. Its totient is φ = 25681920.

The previous prime is 66332723. The next prime is 66332729. The reversal of 66332728 is 82723366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66332723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 158103 + ... + 158521.

It is an arithmetic number, because the mean of its divisors is an integer number (2438100).

Almost surely, 2^66332728 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 66332728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78019200).

66332728 is an abundant number, since it is smaller than the sum of its proper divisors (89705672).

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

66332728 is a wasteful number, since it uses less digits than its factorization.

66332728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700 (or 696 counting only the distinct ones).

The product of its digits is 72576, while the sum is 37.

The square root of 66332728 is about 8144.4906531962. The cubic root of 66332728 is about 404.8019719787.

The spelling of 66332728 in words is "sixty-six million, three hundred thirty-two thousand, seven hundred twenty-eight".