66728385655 has 8 divisors (see below), whose sum is σ = 80075517984. Its totient is φ = 53381738400.

The previous prime is 66728385653. The next prime is 66728385673. The reversal of 66728385655 is 55658382766.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66728385655 - 2¹ = 66728385653 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66728385593 and 66728385602.

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, 342885 + ... + 501025.

It is an arithmetic number, because the mean of its divisors is an integer number (10009439748).

Almost surely, 2^66728385655 is an apocalyptic number.

66728385655 is a deficient number, since it is larger than the sum of its proper divisors (13347132329).

66728385655 is a wasteful number, since it uses less digits than its factorization.

66728385655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242537.

The product of its digits is 72576000, while the sum is 61.

The spelling of 66728385655 in words is "sixty-six billion, seven hundred twenty-eight million, three hundred eighty-five thousand, six hundred fifty-five".