664481018240 has 256 divisors, whose sum is σ = 1873821600000. Its totient is φ = 222950719488.

The previous prime is 664481018239. The next prime is 664481018297. The reversal of 664481018240 is 42810184466.

It is a junction number, because it is equal to n+sod(n) for n = 664481018191 and 664481018200.

It is a congruent number.

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, 4020761 + ... + 4182759.

It is an arithmetic number, because the mean of its divisors is an integer number (7319615625).

Almost surely, 2^664481018240 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 664481018240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (936910800000).

664481018240 is an abundant number, since it is smaller than the sum of its proper divisors (1209340581760).

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

664481018240 is a wasteful number, since it uses less digits than its factorization.

664481018240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162077 (or 162065 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 44.

The spelling of 664481018240 in words is "six hundred sixty-four billion, four hundred eighty-one million, eighteen thousand, two hundred forty".