66728385834 has 32 divisors (see below), whose sum is σ = 146924902080. Its totient is φ = 20035209600.

The previous prime is 66728385797. The next prime is 66728385859. The reversal of 66728385834 is 43858382766.

It is a happy number.

66728385834 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66728385834² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4630587 + ... + 4644974.

It is an arithmetic number, because the mean of its divisors is an integer number (4591403190).

Almost surely, 2^66728385834 is an apocalyptic number.

66728385834 is an abundant number, since it is smaller than the sum of its proper divisors (80196516246).

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

66728385834 is a wasteful number, since it uses less digits than its factorization.

66728385834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9275686.

The product of its digits is 46448640, while the sum is 60.

The spelling of 66728385834 in words is "sixty-six billion, seven hundred twenty-eight million, three hundred eighty-five thousand, eight hundred thirty-four".