66696217776 has 480 divisors, whose sum is σ = 216774125568. Its totient is φ = 19752284160.

The previous prime is 66696217747. The next prime is 66696217799. The reversal of 66696217776 is 67771269666.

66696217776 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 88105590 + ... + 88106346.

Almost surely, 2^66696217776 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 66696217776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108387062784).

66696217776 is an abundant number, since it is smaller than the sum of its proper divisors (150077907792).

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

66696217776 is a wasteful number, since it uses less digits than its factorization.

66696217776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 871 (or 853 counting only the distinct ones).

The product of its digits is 48009024, while the sum is 63.

The spelling of 66696217776 in words is "sixty-six billion, six hundred ninety-six million, two hundred seventeen thousand, seven hundred seventy-six".