656559538320 has 640 divisors, whose sum is σ = 2461818147840. Its totient is φ = 141585776640.

The previous prime is 656559538277. The next prime is 656559538333. The reversal of 656559538320 is 23835955656.

656559538320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 514141522 + ... + 514142798.

It is an arithmetic number, because the mean of its divisors is an integer number (3846590856).

Almost surely, 2^656559538320 is an apocalyptic number.

656559538320 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 656559538320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1230909073920).

656559538320 is an abundant number, since it is smaller than the sum of its proper divisors (1805258609520).

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

656559538320 is a wasteful number, since it uses less digits than its factorization.

656559538320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563 (or 1557 counting only the distinct ones).

The product of its (nonzero) digits is 29160000, while the sum is 57.

The spelling of 656559538320 in words is "six hundred fifty-six billion, five hundred fifty-nine million, five hundred thirty-eight thousand, three hundred twenty".