664625005640 has 64 divisors (see below), whose sum is σ = 1532610668160. Its totient is φ = 259255503360.

The previous prime is 664625005613. The next prime is 664625005643. The reversal of 664625005640 is 46500526466.

It is a happy number.

664625005640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 664625005591 and 664625005600.

It is not an unprimeable number, because it can be changed into a prime (664625005643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 779132 + ... + 1391508.

It is an arithmetic number, because the mean of its divisors is an integer number (23947041690).

Almost surely, 2^664625005640 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 664625005640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (766305334080).

664625005640 is an abundant number, since it is smaller than the sum of its proper divisors (867985662520).

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

664625005640 is a wasteful number, since it uses less digits than its factorization.

664625005640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613062 (or 613058 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 44.

The spelling of 664625005640 in words is "six hundred sixty-four billion, six hundred twenty-five million, five thousand, six hundred forty".