66680740668 has 12 divisors (see below), whose sum is σ = 155588394920. Its totient is φ = 22226913552.

The previous prime is 66680740667. The next prime is 66680740691. The reversal of 66680740668 is 86604708666.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66680740667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2778364183 + ... + 2778364206.

Almost surely, 2^66680740668 is an apocalyptic number.

It is an amenable number.

66680740668 is an abundant number, since it is smaller than the sum of its proper divisors (88907654252).

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

66680740668 is a wasteful number, since it uses less digits than its factorization.

66680740668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5556728396 (or 5556728394 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 57.

The spelling of 66680740668 in words is "sixty-six billion, six hundred eighty million, seven hundred forty thousand, six hundred sixty-eight".