66682728 has 144 divisors (see below), whose sum is σ = 215675460. Its totient is φ = 18547200.

The previous prime is 66682717. The next prime is 66682741. The reversal of 66682728 is 82728666.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 57790404 + 8892324 = 7602^2 + 2982^2 .

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 144418 + ... + 144878.

Almost surely, 2^66682728 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 66682728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107837730).

66682728 is an abundant number, since it is smaller than the sum of its proper divisors (148992732).

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

66682728 is a wasteful number, since it uses less digits than its factorization.

66682728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 514 counting only the distinct ones).

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

The square root of 66682728 is about 8165.9493018265. The cubic root of 66682728 is about 405.5126931815.

The spelling of 66682728 in words is "sixty-six million, six hundred eighty-two thousand, seven hundred twenty-eight".