667438718728 has 32 divisors (see below), whose sum is σ = 1295660059200. Its totient is φ = 321948198208.

The previous prime is 667438718711. The next prime is 667438718809. The reversal of 667438718728 is 827817834766.

667438718728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 892426 + ... + 1459897.

It is an arithmetic number, because the mean of its divisors is an integer number (40489376850).

Almost surely, 2^667438718728 is an apocalyptic number.

It is an amenable number.

667438718728 is a deficient number, since it is larger than the sum of its proper divisors (628221340472).

667438718728 is a wasteful number, since it uses less digits than its factorization.

667438718728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353581 (or 2353577 counting only the distinct ones).

The product of its digits is 151732224, while the sum is 67.

The spelling of 667438718728 in words is "six hundred sixty-seven billion, four hundred thirty-eight million, seven hundred eighteen thousand, seven hundred twenty-eight".