66695166720 has 720 divisors, whose sum is σ = 293761554240. Its totient is φ = 14069956608.

The previous prime is 66695166709. The next prime is 66695166827. The reversal of 66695166720 is 2766159666.

It is a tau number, because it is divible by the number of its divisors (720).

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

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 79 ways as a sum of consecutive naturals, for example, 9431346 + ... + 9438414.

Almost surely, 2^66695166720 is an apocalyptic number.

66695166720 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 66695166720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146880777120).

66695166720 is an abundant number, since it is smaller than the sum of its proper divisors (227066387520).

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

66695166720 is a wasteful number, since it uses less digits than its factorization.

66695166720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7122 (or 7099 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 54.

The spelling of 66695166720 in words is "sixty-six billion, six hundred ninety-five million, one hundred sixty-six thousand, seven hundred twenty".