660618889920 has 336 divisors, whose sum is σ = 2480335603200. Its totient is φ = 160052275200.

The previous prime is 660618889841. The next prime is 660618889937. The reversal of 660618889920 is 29988816066.

660618889920 is a `hidden beast` number, since 6 + 6 + 0 + 618 + 8 + 8 + 9 + 9 + 2 + 0 = 666.

660618889920 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 47 ways as a sum of consecutive naturals, for example, 61168681 + ... + 61179479.

It is an arithmetic number, because the mean of its divisors is an integer number (7381951200).

Almost surely, 2^660618889920 is an apocalyptic number.

660618889920 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 660618889920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1240167801600).

660618889920 is an abundant number, since it is smaller than the sum of its proper divisors (1819716713280).

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

660618889920 is a wasteful number, since it uses less digits than its factorization.

660618889920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12764 (or 12751 counting only the distinct ones).

The product of its (nonzero) digits is 17915904, while the sum is 63.

The spelling of 660618889920 in words is "six hundred sixty billion, six hundred eighteen million, eight hundred eighty-nine thousand, nine hundred twenty".