66644330688 has 336 divisors, whose sum is σ = 223336713600. Its totient is φ = 19425070080.

The previous prime is 66644330681. The next prime is 66644330737. The reversal of 66644330688 is 88603344666.

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

It is not an unprimeable number, because it can be changed into a prime (66644330681) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5542603 + ... + 5554613.

It is an arithmetic number, because the mean of its divisors is an integer number (664692600).

Almost surely, 2^66644330688 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 66644330688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111668356800).

66644330688 is an abundant number, since it is smaller than the sum of its proper divisors (156692382912).

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

66644330688 is a wasteful number, since it uses less digits than its factorization.

66644330688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12077 (or 12048 counting only the distinct ones).

The product of its (nonzero) digits is 11943936, while the sum is 54.

The spelling of 66644330688 in words is "sixty-six billion, six hundred forty-four million, three hundred thirty thousand, six hundred eighty-eight".