66321786384 has 480 divisors, whose sum is σ = 244087234560. Its totient is φ = 16348262400.

The previous prime is 66321786359. The next prime is 66321786389. The reversal of 66321786384 is 48368712366.

66321786384 is a `hidden beast` number, since 66 + 32 + 178 + 6 + 384 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 66321786384.

It is not an unprimeable number, because it can be changed into a prime (66321786389) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10089819 + ... + 10096389.

It is an arithmetic number, because the mean of its divisors is an integer number (508515072).

Almost surely, 2^66321786384 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 66321786384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122043617280).

66321786384 is an abundant number, since it is smaller than the sum of its proper divisors (177765448176).

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

66321786384 is a wasteful number, since it uses less digits than its factorization.

66321786384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6659 (or 6650 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 54.

The spelling of 66321786384 in words is "sixty-six billion, three hundred twenty-one million, seven hundred eighty-six thousand, three hundred eighty-four".