664578522564 has 72 divisors (see below), whose sum is σ = 1705479535200. Its totient is φ = 201268151040.

The previous prime is 664578522541. The next prime is 664578522589. The reversal of 664578522564 is 465225875466.

It is a super-2 number, since 2×664578522564² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664578522498 and 664578522507.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2332252 + ... + 2601644.

Almost surely, 2^664578522564 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 664578522564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (852739767600).

664578522564 is an abundant number, since it is smaller than the sum of its proper divisors (1040901012636).

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

664578522564 is a wasteful number, since it uses less digits than its factorization.

664578522564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271121 (or 271108 counting only the distinct ones).

The product of its digits is 96768000, while the sum is 60.

The spelling of 664578522564 in words is "six hundred sixty-four billion, five hundred seventy-eight million, five hundred twenty-two thousand, five hundred sixty-four".