66728385652 has 24 divisors (see below), whose sum is σ = 124071643080. Its totient is φ = 31401584000.

The previous prime is 66728385629. The next prime is 66728385653. The reversal of 66728385652 is 25658382766.

66728385652 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 13225920016 + 53502465636 = 115004^2 + 231306^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66728385653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1678099 + ... + 1717402.

It is an arithmetic number, because the mean of its divisors is an integer number (5169651795).

Almost surely, 2^66728385652 is an apocalyptic number.

It is an amenable number.

66728385652 is a deficient number, since it is larger than the sum of its proper divisors (57343257428).

66728385652 is a wasteful number, since it uses less digits than its factorization.

66728385652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3395556 (or 3395520 counting only the distinct ones).

The product of its digits is 29030400, while the sum is 58.

The spelling of 66728385652 in words is "sixty-six billion, seven hundred twenty-eight million, three hundred eighty-five thousand, six hundred fifty-two".