664821168860 has 48 divisors (see below), whose sum is σ = 1514304318240. Its totient is φ = 244181084160.

The previous prime is 664821168787. The next prime is 664821168919. The reversal of 664821168860 is 68861128466.

It is a junction number, because it is equal to n+sod(n) for n = 664821168796 and 664821168805.

It is a congruent number.

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, 23831870 + ... + 23859749.

It is an arithmetic number, because the mean of its divisors is an integer number (31548006630).

Almost surely, 2^664821168860 is an apocalyptic number.

It is an amenable number.

664821168860 is an abundant number, since it is smaller than the sum of its proper divisors (849483149380).

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

664821168860 is a wasteful number, since it uses less digits than its factorization.

664821168860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47691686 (or 47691684 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 56.

The spelling of 664821168860 in words is "six hundred sixty-four billion, eight hundred twenty-one million, one hundred sixty-eight thousand, eight hundred sixty".