66728894456 has 16 divisors (see below), whose sum is σ = 142990488240. Its totient is φ = 28598097600.

The previous prime is 66728894447. The next prime is 66728894503. The reversal of 66728894456 is 65449882766.

It is a junction number, because it is equal to n+sod(n) for n = 66728894392 and 66728894401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 595793645 + ... + 595793756.

It is an arithmetic number, because the mean of its divisors is an integer number (8936905515).

Almost surely, 2^66728894456 is an apocalyptic number.

It is an amenable number.

66728894456 is an abundant number, since it is smaller than the sum of its proper divisors (76261593784).

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

66728894456 is a wasteful number, since it uses less digits than its factorization.

66728894456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191587414 (or 1191587410 counting only the distinct ones).

The product of its digits is 139345920, while the sum is 65.

The spelling of 66728894456 in words is "sixty-six billion, seven hundred twenty-eight million, eight hundred ninety-four thousand, four hundred fifty-six".