66387688560 has 320 divisors, whose sum is σ = 237199104000. Its totient is φ = 17046328320.

The previous prime is 66387688559. The next prime is 66387688607. The reversal of 66387688560 is 6588678366.

66387688560 is a `hidden beast` number, since 6 + 6 + 3 + 8 + 7 + 68 + 8 + 560 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26996611 + ... + 26999069.

It is an arithmetic number, because the mean of its divisors is an integer number (741247200).

Almost surely, 2^66387688560 is an apocalyptic number.

66387688560 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 66387688560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118599552000).

66387688560 is an abundant number, since it is smaller than the sum of its proper divisors (170811415440).

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

66387688560 is a wasteful number, since it uses less digits than its factorization.

66387688560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2941 (or 2929 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 63.

The spelling of 66387688560 in words is "sixty-six billion, three hundred eighty-seven million, six hundred eighty-eight thousand, five hundred sixty".