664622660640 has 48 divisors (see below), whose sum is σ = 2093561382528. Its totient is φ = 177232709376.

The previous prime is 664622660623. The next prime is 664622660651. The reversal of 664622660640 is 46066226466.

664622660640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 664622660640.

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, 692314792 + ... + 692315751.

It is an arithmetic number, because the mean of its divisors is an integer number (43615862136).

Almost surely, 2^664622660640 is an apocalyptic number.

664622660640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664622660640 is an abundant number, since it is smaller than the sum of its proper divisors (1428938721888).

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

664622660640 is a wasteful number, since it uses less digits than its factorization.

664622660640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1384630561 (or 1384630553 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 48.

The spelling of 664622660640 in words is "six hundred sixty-four billion, six hundred twenty-two million, six hundred sixty thousand, six hundred forty".