644166666204 has 24 divisors (see below), whose sum is σ = 1503112598400. Its totient is φ = 214714072944.

The previous prime is 644166666197. The next prime is 644166666239. The reversal of 644166666204 is 402666661446.

It is a congruent number.

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, 684904 + ... + 1325679.

It is an arithmetic number, because the mean of its divisors is an integer number (62629691600).

Almost surely, 2^644166666204 is an apocalyptic number.

It is an amenable number.

644166666204 is an abundant number, since it is smaller than the sum of its proper divisors (858945932196).

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

644166666204 is a wasteful number, since it uses less digits than its factorization.

644166666204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2037289 (or 2037287 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 51.

The spelling of 644166666204 in words is "six hundred forty-four billion, one hundred sixty-six million, six hundred sixty-six thousand, two hundred four".