66388608 has 288 divisors, whose sum is σ = 232951680. Its totient is φ = 17971200.

The previous prime is 66388561. The next prime is 66388657. The reversal of 66388608 is 80688366.

66388608 is a `hidden beast` number, since 6 + 6 + 38 + 8 + 608 = 666.

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

It is a zygodrome in base 4.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2141553 + ... + 2141583.

It is an arithmetic number, because the mean of its divisors is an integer number (808860).

Almost surely, 2^66388608 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 66388608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116475840).

66388608 is an abundant number, since it is smaller than the sum of its proper divisors (166563072).

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

66388608 is a wasteful number, since it uses less digits than its factorization.

66388608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 66388608 is about 8147.9204708932. The cubic root of 66388608 is about 404.9156111325.

The spelling of 66388608 in words is "sixty-six million, three hundred eighty-eight thousand, six hundred eight".