66535406208 has 384 divisors, whose sum is σ = 217532952000. Its totient is φ = 20149420032.

The previous prime is 66535406183. The next prime is 66535406209. The reversal of 66535406208 is 80260453566.

66535406208 is a `hidden beast` number, since 6 + 6 + 5 + 35 + 406 + 208 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is not an unprimeable number, because it can be changed into a prime (66535406209) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15332103 + ... + 15336441.

Almost surely, 2^66535406208 is an apocalyptic number.

66535406208 is a gapful number since it is divisible by the number (68) 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 66535406208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108766476000).

66535406208 is an abundant number, since it is smaller than the sum of its proper divisors (150997545792).

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

66535406208 is a wasteful number, since it uses less digits than its factorization.

66535406208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4414 (or 4390 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 45.

The spelling of 66535406208 in words is "sixty-six billion, five hundred thirty-five million, four hundred six thousand, two hundred eight".