66728448 has 100 divisors (see below), whose sum is σ = 199290630. Its totient is φ = 22228992.

The previous prime is 66728423. The next prime is 66728477. The reversal of 66728448 is 84482766.

It can be written as a sum of positive squares in only one way, i.e., 38340864 + 28387584 = 6192^2 + 5328^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 40668 + ... + 42276.

Almost surely, 2^66728448 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 66728448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99645315).

66728448 is an abundant number, since it is smaller than the sum of its proper divisors (132562182).

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

66728448 is an equidigital number, since it uses as much as digits as its factorization.

66728448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1639 (or 1614 counting only the distinct ones).

The product of its digits is 516096, while the sum is 45.

The square root of 66728448 is about 8168.7482517213. The cubic root of 66728448 is about 405.6053498822.

It can be divided in two parts, 66728 and 448, that added together give a palindrome (67176).

The spelling of 66728448 in words is "sixty-six million, seven hundred twenty-eight thousand, four hundred forty-eight".