664643303660 has 96 divisors (see below), whose sum is σ = 1626782814720. Its totient is φ = 223379785728.

The previous prime is 664643303659. The next prime is 664643303683. The reversal of 664643303660 is 66303346466.

It is a happy number.

It is a super-2 number, since 2×664643303660² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2801807 + ... + 3029753.

It is an arithmetic number, because the mean of its divisors is an integer number (16945654320).

Almost surely, 2^664643303660 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 664643303660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (813391407360).

664643303660 is an abundant number, since it is smaller than the sum of its proper divisors (962139511060).

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

664643303660 is a wasteful number, since it uses less digits than its factorization.

664643303660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228375 (or 228373 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 47.

The spelling of 664643303660 in words is "six hundred sixty-four billion, six hundred forty-three million, three hundred three thousand, six hundred sixty".