66381931296 has 432 divisors, whose sum is σ = 210640510080. Its totient is φ = 20558499840.

The previous prime is 66381931271. The next prime is 66381931303. The reversal of 66381931296 is 69213918366.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (54).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 244951641 + ... + 244951911.

Almost surely, 2^66381931296 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 66381931296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105320255040).

66381931296 is an abundant number, since it is smaller than the sum of its proper divisors (144258578784).

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

66381931296 is a wasteful number, since it uses less digits than its factorization.

66381931296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439 (or 402 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 54.

The spelling of 66381931296 in words is "sixty-six billion, three hundred eighty-one million, nine hundred thirty-one thousand, two hundred ninety-six".