66756345720 has 256 divisors, whose sum is σ = 218102976000. Its totient is φ = 16288045056.

The previous prime is 66756345713. The next prime is 66756345731. The reversal of 66756345720 is 2754365766.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11723194 + ... + 11728886.

It is an arithmetic number, because the mean of its divisors is an integer number (851964750).

Almost surely, 2^66756345720 is an apocalyptic number.

66756345720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66756345720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109051488000).

66756345720 is an abundant number, since it is smaller than the sum of its proper divisors (151346630280).

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

66756345720 is a wasteful number, since it uses less digits than its factorization.

66756345720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5902 (or 5898 counting only the distinct ones).

The product of its (nonzero) digits is 6350400, while the sum is 51.

The spelling of 66756345720 in words is "sixty-six billion, seven hundred fifty-six million, three hundred forty-five thousand, seven hundred twenty".