66440481408 has 576 divisors, whose sum is σ = 230736729600. Its totient is φ = 18286055424.

The previous prime is 66440481403. The next prime is 66440481431. The reversal of 66440481408 is 80418404466.

66440481408 is a `hidden beast` number, since 66 + 440 + 4 + 8 + 140 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is not an unprimeable number, because it can be changed into a prime (66440481403) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 209591266 + ... + 209591582.

It is an arithmetic number, because the mean of its divisors is an integer number (400584600).

Almost surely, 2^66440481408 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 66440481408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115368364800).

66440481408 is an abundant number, since it is smaller than the sum of its proper divisors (164296248192).

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

66440481408 is a wasteful number, since it uses less digits than its factorization.

66440481408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 589824, while the sum is 45.

The spelling of 66440481408 in words is "sixty-six billion, four hundred forty million, four hundred eighty-one thousand, four hundred eight".