66719793888 has 72 divisors (see below), whose sum is σ = 206983006776. Its totient is φ = 20218118400.

The previous prime is 66719793857. The next prime is 66719793911. The reversal of 66719793888 is 88839791766.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10527103 + ... + 10533438.

It is an arithmetic number, because the mean of its divisors is an integer number (2874763983).

Almost surely, 2^66719793888 is an apocalyptic number.

It is an amenable number.

66719793888 is an abundant number, since it is smaller than the sum of its proper divisors (140263212888).

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

66719793888 is a wasteful number, since it uses less digits than its factorization.

66719793888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21060568 (or 21060557 counting only the distinct ones).

The product of its digits is 219469824, while the sum is 72.

The spelling of 66719793888 in words is "sixty-six billion, seven hundred nineteen million, seven hundred ninety-three thousand, eight hundred eighty-eight".