66827664788 has 12 divisors (see below), whose sum is σ = 116952866100. Its totient is φ = 33412560192.

The previous prime is 66827664781. The next prime is 66827664791. The reversal of 66827664788 is 88746672866.

It can be written as a sum of positive squares in 2 ways, for example, as 45968217604 + 20859447184 = 214402^2 + 144428^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66827664781) 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, 194531 + ... + 414122.

It is an arithmetic number, because the mean of its divisors is an integer number (9746072175).

Almost surely, 2^66827664788 is an apocalyptic number.

It is an amenable number.

66827664788 is a deficient number, since it is larger than the sum of its proper divisors (50125201312).

66827664788 is a wasteful number, since it uses less digits than its factorization.

66827664788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636106 (or 636104 counting only the distinct ones).

The product of its digits is 260112384, while the sum is 68.

The spelling of 66827664788 in words is "sixty-six billion, eight hundred twenty-seven million, six hundred sixty-four thousand, seven hundred eighty-eight".