66728759 has 4 divisors (see below), whose sum is σ = 66892320. Its totient is φ = 66565200.

The previous prime is 66728737. The next prime is 66728807. The reversal of 66728759 is 95782766.

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 66728759 - 2⁸ = 66728503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66718759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81167 + ... + 81984.

It is an arithmetic number, because the mean of its divisors is an integer number (16723080).

Almost surely, 2^66728759 is an apocalyptic number.

66728759 is a deficient number, since it is larger than the sum of its proper divisors (163561).

66728759 is a wasteful number, since it uses less digits than its factorization.

66728759 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163560.

The product of its digits is 1270080, while the sum is 50.

The square root of 66728759 is about 8168.7672876634. The cubic root of 66728759 is about 405.6059800136.

The spelling of 66728759 in words is "sixty-six million, seven hundred twenty-eight thousand, seven hundred fifty-nine".