65881618866 has 96 divisors (see below), whose sum is σ = 170813897280. Its totient is φ = 18767210112.

The previous prime is 65881618771. The next prime is 65881618867. The reversal of 65881618866 is 66881618856.

65881618866 is a `hidden beast` number, since 6 + 5 + 8 + 8 + 1 + 618 + 8 + 6 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65881618867) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 854761 + ... + 928643.

It is an arithmetic number, because the mean of its divisors is an integer number (1779311430).

Almost surely, 2^65881618866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65881618866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85406948640).

65881618866 is an abundant number, since it is smaller than the sum of its proper divisors (104932278414).

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

65881618866 is a wasteful number, since it uses less digits than its factorization.

65881618866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74245 (or 74232 counting only the distinct ones).

The product of its digits is 26542080, while the sum is 63.

The spelling of 65881618866 in words is "sixty-five billion, eight hundred eighty-one million, six hundred eighteen thousand, eight hundred sixty-six".