66662728 has 64 divisors (see below), whose sum is σ = 141926400. Its totient is φ = 29090880.

The previous prime is 66662723. The next prime is 66662731. The reversal of 66662728 is 82726666.

66662728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is not an unprimeable number, because it can be changed into a prime (66662723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 298825 + ... + 299047.

It is an arithmetic number, because the mean of its divisors is an integer number (2217600).

Almost surely, 2^66662728 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 66662728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70963200).

66662728 is an abundant number, since it is smaller than the sum of its proper divisors (75263672).

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

66662728 is a wasteful number, since it uses less digits than its factorization.

66662728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362 (or 358 counting only the distinct ones).

The product of its digits is 290304, while the sum is 43.

The square root of 66662728 is about 8164.7246126247. The cubic root of 66662728 is about 405.4721476255.

The spelling of 66662728 in words is "sixty-six million, six hundred sixty-two thousand, seven hundred twenty-eight".