664843564416 has 128 divisors (see below), whose sum is σ = 1775829800160. Its totient is φ = 220383313920.

The previous prime is 664843564409. The next prime is 664843564433. The reversal of 664843564416 is 614465348466.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51368506 + ... + 51381446.

Almost surely, 2^664843564416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664843564416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (887914900080).

664843564416 is an abundant number, since it is smaller than the sum of its proper divisors (1110986235744).

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

664843564416 is a wasteful number, since it uses less digits than its factorization.

664843564416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13692 (or 13680 counting only the distinct ones).

The product of its digits is 39813120, while the sum is 57.

The spelling of 664843564416 in words is "six hundred sixty-four billion, eight hundred forty-three million, five hundred sixty-four thousand, four hundred sixteen".