664345059840 has 1440 divisors, whose sum is σ = 2944360298880. Its totient is φ = 135470776320.

The previous prime is 664345059827. The next prime is 664345059841. The reversal of 664345059840 is 48950543466.

664345059840 is a `hidden beast` number, since 6 + 6 + 4 + 3 + 4 + 5 + 0 + 598 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is not an unprimeable number, because it can be changed into a prime (664345059841) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1151377632 + ... + 1151378208.

It is an arithmetic number, because the mean of its divisors is an integer number (2044694652).

Almost surely, 2^664345059840 is an apocalyptic number.

664345059840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664345059840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1472180149440).

664345059840 is an abundant number, since it is smaller than the sum of its proper divisors (2280015239040).

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

664345059840 is a wasteful number, since it uses less digits than its factorization.

664345059840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694 (or 664 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 54.

The spelling of 664345059840 in words is "six hundred sixty-four billion, three hundred forty-five million, fifty-nine thousand, eight hundred forty".