66728956679 has 16 divisors (see below), whose sum is σ = 83204858880. Its totient is φ = 51990142560.

The previous prime is 66728956661. The next prime is 66728956717. The reversal of 66728956679 is 97665982766.

66728956679 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 66728956679 - 2⁸ = 66728956423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66728956579) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 626957 + ... + 725625.

It is an arithmetic number, because the mean of its divisors is an integer number (5200303680).

Almost surely, 2^66728956679 is an apocalyptic number.

66728956679 is a deficient number, since it is larger than the sum of its proper divisors (16475902201).

66728956679 is a wasteful number, since it uses less digits than its factorization.

66728956679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107470.

The product of its digits is 411505920, while the sum is 71.

The spelling of 66728956679 in words is "sixty-six billion, seven hundred twenty-eight million, nine hundred fifty-six thousand, six hundred seventy-nine".