66557177568 has 288 divisors, whose sum is σ = 224080496640. Its totient is φ = 18337674240.

The previous prime is 66557177551. The next prime is 66557177587. The reversal of 66557177568 is 86577175566.

66557177568 is a `hidden beast` number, since 6 + 6 + 5 + 57 + 17 + 7 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

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, 19184538 + ... + 19188006.

It is an arithmetic number, because the mean of its divisors is an integer number (778057280).

Almost surely, 2^66557177568 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 66557177568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112040248320).

66557177568 is an abundant number, since it is smaller than the sum of its proper divisors (157523319072).

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

66557177568 is a wasteful number, since it uses less digits than its factorization.

66557177568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3830 (or 3819 counting only the distinct ones).

The product of its digits is 74088000, while the sum is 63.

The spelling of 66557177568 in words is "sixty-six billion, five hundred fifty-seven million, one hundred seventy-seven thousand, five hundred sixty-eight".