66666066912 has 144 divisors (see below), whose sum is σ = 195296708880. Its totient is φ = 21558220800.

The previous prime is 66666066869. The next prime is 66666066913. The reversal of 66666066912 is 21966066666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×66666066912² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66666066913) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2097862 + ... + 2129402.

It is an arithmetic number, because the mean of its divisors is an integer number (1356227145).

Almost surely, 2^66666066912 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 66666066912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97648354440).

66666066912 is an abundant number, since it is smaller than the sum of its proper divisors (128630641968).

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

66666066912 is a wasteful number, since it uses less digits than its factorization.

66666066912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31777 (or 31766 counting only the distinct ones).

The product of its (nonzero) digits is 5038848, while the sum is 54.

The spelling of 66666066912 in words is "sixty-six billion, six hundred sixty-six million, sixty-six thousand, nine hundred twelve".