66728385835 has 4 divisors (see below), whose sum is σ = 80074063008. Its totient is φ = 53382708664.

The previous prime is 66728385797. The next prime is 66728385859. The reversal of 66728385835 is 53858382766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66728385835 - 2⁷ = 66728385707 is a prime.

It is a super-2 number, since 2×66728385835² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6672838579 + ... + 6672838588.

It is an arithmetic number, because the mean of its divisors is an integer number (20018515752).

Almost surely, 2^66728385835 is an apocalyptic number.

66728385835 is a deficient number, since it is larger than the sum of its proper divisors (13345677173).

66728385835 is a wasteful number, since it uses less digits than its factorization.

66728385835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13345677172.

The product of its digits is 58060800, while the sum is 61.

The spelling of 66728385835 in words is "sixty-six billion, seven hundred twenty-eight million, three hundred eighty-five thousand, eight hundred thirty-five".