66391268320 has 384 divisors, whose sum is σ = 187578115200. Its totient is φ = 21979496448.

The previous prime is 66391268299. The next prime is 66391268329. The reversal of 66391268320 is 2386219366.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66391268329) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 60741694 + ... + 60742786.

It is an arithmetic number, because the mean of its divisors is an integer number (488484675).

Almost surely, 2^66391268320 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 66391268320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93789057600).

66391268320 is an abundant number, since it is smaller than the sum of its proper divisors (121186846880).

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

66391268320 is a wasteful number, since it uses less digits than its factorization.

66391268320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222 (or 1214 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 46.

The spelling of 66391268320 in words is "sixty-six billion, three hundred ninety-one million, two hundred sixty-eight thousand, three hundred twenty".