66756479505408 has 2112 divisors, whose sum is σ = 259311890073600. Its totient is φ = 16644591452160.

The previous prime is 66756479505389. The next prime is 66756479505409. The reversal of 66756479505408 is 80450597465766.

66756479505408 is a `hidden beast` number, since 6 + 6 + 7 + 5 + 6 + 4 + 79 + 5 + 0 + 540 + 8 = 666.

66756479505408 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (2112).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66756479505409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 176138468163 + ... + 176138468541.

Almost surely, 2^{66756479505408} 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 66756479505408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129655945036800).

66756479505408 is an abundant number, since it is smaller than the sum of its proper divisors (192555410568192).

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

66756479505408 is a wasteful number, since it uses less digits than its factorization.

66756479505408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778 (or 748 counting only the distinct ones).

The product of its (nonzero) digits is 1524096000, while the sum is 72.

The spelling of 66756479505408 in words is "sixty-six trillion, seven hundred fifty-six billion, four hundred seventy-nine million, five hundred five thousand, four hundred eight".