66116266866 has 72 divisors (see below), whose sum is σ = 155786350356. Its totient is φ = 20255938560.

The previous prime is 66116266829. The next prime is 66116266897. The reversal of 66116266866 is 66866261166.

66116266866 is a `hidden beast` number, since 6 + 6 + 1 + 1 + 626 + 6 + 8 + 6 + 6 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 19622126241 + 46494140625 = 140079^2 + 215625^2 .

It is a super-2 number, since 2×66116266866² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 662146 + ... + 755426.

Almost surely, 2^66116266866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66116266866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77893175178).

66116266866 is an abundant number, since it is smaller than the sum of its proper divisors (89670083490).

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

66116266866 is a wasteful number, since it uses less digits than its factorization.

66116266866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93548 (or 93532 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The spelling of 66116266866 in words is "sixty-six billion, one hundred sixteen million, two hundred sixty-six thousand, eight hundred sixty-six".